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Drones have been increasing in popularity and are able to cause skin injuries ranging from minor abrasions to severe lacerations. The objective of this study was to determine the aspects of drone blades that cause injuries, and to help manufacturers design safer drones by suggesting an injury threshold. The blade tip thickness, blade length, angular velocity, and blade tip speed of a variety of popular drones were measured. The injury caused by each drone blade contacting a fetal bovine skin surrogate at different speeds was recorded. Blade tip speed had the highest correlation to injury severity, while blade tip thickness, blade length, and rpm had little to no correlation with the resulting injury. Blade tip speeds above 25 m/s resulted in minor abrasions, and speeds above 60 m/s resulted in minor lacerations. To prevent severe injuries, drone manufacturers should design drones with blade tip speeds below the threshold of 60 m/s.

Introduction ACE-083 is a locally acting follistatin-based therapeutic that binds myostatin and other muscle regulators and has been shown to increase muscle mass and force in neuromuscular disease mouse models. This first-in-human study examined these effects. Methods In this phase 1, randomized, double-blind, placebo-controlled, dose-ranging study in healthy postmenopausal women, ACE-083 (50-200 mg) or placebo was administered unilaterally into rectus femoris (RF) or tibialis anterior (TA) muscles as 1 or 2 doses 3 weeks apart. Results Fifty-eight postmenopausal women were enrolled, 42 ACE-083 and 16 placebo. No serious adverse events (AE), dose-limiting toxicities, or discontinuations resulting from AEs occurred. Maximum (mean ± SD) increases in RF and TA muscle volume were 14.5% ± 4.5% and 8.9% ± 4.7%, respectively. No significant changes in mean muscle strength were observed. Discussion ACE-083 was well tolerated and resulted in significant targeted muscle growth. ACE-083 may have the potential to increase muscle mass in a wide range of neuromuscular disorders. Muscle Nerve 57: 921-926, 2018.

Introduction Elevated interleukin (IL)-6 occurs in patients with active rheumatoid arthritis (RA), which has been shown to lead to a decrease in cytochrome P450 (CYP) enzyme activity and alterations in drug concentrations metabolized by CYP. IL-6 signaling blockade by IL-6 receptor (IL-6R) antagonists may reverse this effect of IL-6 and restore CYP activity. This study evaluated the pharmacokinetic profile of simvastatin (a CYP3A4 substrate) before and 1 week after a single dose of sarilumab (a human monoclonal antibody [mAb] blocking the IL-6Rα) in patients with RA, to assess potential interaction. Methods Nineteen patients with active RA received oral simvastatin 40 mg 1 day before and 7 days after subcutaneous injection of sarilumab 200 mg. The pharmacokinetic parameters of simvastatin and its primary metabolite, β-hydroxy-simvastatin acid, were calculated using noncompartmental analysis. Results Compared with simvastatin alone, single-dose simvastatin administration 7 days after single-dose sarilumab administration in patients with RA resulted in reduced simvastatin and β-hydroxy-simvastatin acid exposure in plasma. Mean effect ratios (90 % confidence interval) for simvastatin peak plasma concentration (C max) and area under the concentration–time curve extrapolated to infinity (AUC∞) were 54.1 % (42.2–69.4 %) and 54.7 % (47.2–63.3 %), respectively. No changes occurred in time to C max or half-life for either simvastatin or β-hydroxy-simvastatin acid after sarilumab administration. Conclusions Sarilumab treatment resulted in a reduction in exposure of simvastatin, consistent with reversal of IL-6-mediated CYP3A4 suppression in patients with active RA, as was reported for tocilizumab with simvastatin and for sirukumab with midazolam. Clinical trial registration number NCT02017639. Electronic supplementary material The online version of this article (doi:10.1007/s40262-016-0462-8) contains supplementary material, which is available to authorized users.

Objective: To establish if there is a role for gabapentin or nortriptyline in the treatment of chronic orchialgia. Methods: Twenty-six consecutive patients with chronic orchialgia were seen in the chronic pain clinic by a multidisciplinary team. A pain questionnaire was completed prior to commencing either gabapentin or nortriptyline. They were reviewed at 3 months and a repeat questionnaire completed. A 50% improvement in pain was considered successful. Results: Complete data was available for 19 patients. Overall, 61.5% of patients commenced on gabapentin and 66.6% of patients commenced on nortriptyline had a greater than 50% improvement in pain. Patients with post-vasectomy testicular pain were considered as a subgroup. None of these patients had a greater than 50% improvement in pain. However, 80% of patients in the subgroup with idiopathic chronic orchialgia had a greater than 50% improvement in pain. Conclusion: Although this is a small study, it appears that gabapentin and nortriptyline are effective in the treatment of idiopathic chronic orchialgia but not post-vasectomy pain.

Recovery and the postoperative period are times of significant physiological change, and, as with induction, the risks of complications and the need for rapid responses are at their greatest. The importance of controlled management and monitoring is discussed in this article. Airway control and breathing remain the most important aspects, and these are principally affected by residual muscular blockade, changing inhalational gas mixtures and returning reflex and conscious activity. The issues surrounding the assessment and appropriate management of muscular block, and the importance of maintaining oxygenation and normocapnia are emphasized. The various groups of sedating agents and the difficulties in their reversal are reviewed. The recovery period on the general ward is also examined, with particular emphasis on the provision and value of oxygenation, fluid management and analgesia.

Background Very late antigen (VLA-4) antagonists have been proposed as potential therapies for diseases in which cell recruitment and accumulation are causative. Asthma, which is characterized by airway inflammation involving the accumulation of eosinophils and mononuclear cells, is one such disease. Objective We sought to assess the effect of IVL745, a VLA-4 antagonist, on the early and late asthmatic response (LAR) and on markers of airway inflammation after allergen inhalation. Methods The study was of a placebo-controlled, double-blind, randomized, 2-way crossover design. Sixteen subjects with mild-to-moderate asthma controlled with short-acting β 2 -agonists only and with a LAR to inhaled allergen participated in the study. At one treatment period they took 20 mg of IVL745 and one treatment period placebo. Both treatments were taken twice daily for 7 days, with a single dose on day 8. Treatments were separated by a washout period of at least 2 weeks. On day 7 of each treatment period, sputum was induced and collected, and exhaled nitric oxide (NO) was measured. On day 8, an inhaled bolus allergen challenge was performed, and blood was taken for pharmacokinetics. On day 9, exhaled NO was measured, and a methacholine challenge was done. On day 10, sputum was induced and collected. Adverse events, peak expiratory flow (PEF), use of short-acting β 2 -agonists, and asthma symptoms were recorded daily throughout the study. Results There was no statistically significant difference between IVL745 and placebo in the effect on the LAR after allergen challenge, as measured by the area under the curve of the percentage change in FEV 1 from the prechallenge baseline (mean [SEM], −81.99 [18.80] after IVL745 and −72.58 [21.29] after placebo; 95% CI of difference, −36 to 16.8; P = .46) or by the maximum percentage change from the prechallenge baseline (mean [SEM], −23.44 [4.73] after IVL745 and −21.30 [5.17] after placebo; 95% CI of difference, −11 to 6.29; P = .60). There was a statistically significant decrease in the percentage of eosinophils in sputum on day 7 of treatment with IVL745 (mean [SEM], 7.32 [1.46]) compared with placebo (mean [SEM], 15.00 [1.92]; 95% CI of difference, −13 to −1.2; P = .02). There was no statistically significant difference between IVL745 and placebo with respect to the early asthmatic response, methacholine hyperresponsiveness, exhaled NO, postallergen sputum, symptoms, inhaled β 2 -agonist use, or PEF. Conclusion In patients with mild-to-moderate atopic asthma, IVL745 did not affect the early and late response to inhaled allergen or markers of airway inflammation, except for a modest reduction in sputum eosinophils.

A new reflective configuration for a monolithically integrated channel selector with power monitor is proposed. One star coupler, one arrayed waveguide grating, and a minimum number of semiconductor optical amplifier (SOA) gates are used to achieve loss-free transmission. A 32-channel device controlled by only 12 SOA gates is realized in InP. Low on-chip losses result in strongly reduced bias currents and an improved signal to noise ratio compared to previously demonstrated devices. The use of SOAs allows for switching on a nanosecond time scale.

A mode-adapted semiconductor optical amplifier (SOA) has been fabricated and packaged. At the gain peak, 1500 nm, the fiber to fiber gain was measured to be 32.5 dB. Statistics for eight packaged devices indicate that a fiber-to-fiber gain of 26.3 dB /spl plusmn/ 1.3 dB and a saturation output power of 12.4 dBm /spl plusmn/ 0.4 dBm are typical at a bias of 500 mA for /spl lambda/ = 1550 nm. Polarization sensitivity at 1550 nm was measured to be 1.1 dB /spl plusmn/ 0.4 dB and the transverse electric (TE) polarization state noise figure (NF) was determined to be 7.0 dB /spl plusmn/ 0.5 dB. The coupling loss was 1.3 dB /spl plusmn/ 0.1 dB per facet. This SOA, with a 1.3-nm filter, was used as an optical preamplifier in a 10-Gb/s return-to-zero (RZ) system testbed with a pseudorandom binary sequence (PRBS) of 2/sup 31/ -1. A 14.5-dB improvement in receiver sensitivity was observed at a bit error rate (BER) of 10/sup -11/.

Postoperative nausea and vomiting (PONV) is a common and distressing event following surgery. About one in four patients are affected. It has an associated morbidity and mortality caused by both the direct effects of vomiting and the difficulties in managing other aspects of postoperative care. This article discusses the five principal areas to be considered when assessing and managing the risks of PONV: premorbid patient issues; the immediate preoperative situation; the nature of the proposed surgery; anaesthetic technique; and the postoperative circumstances. Advances in the understanding of normal physiology and the pathophysiological states induced by any surgical intervention have revealed that a multimodal approach is essential to manage this condition. Treatment must begin in the preoperative period and aim to reduce both physical and psychological risk factors. The anaesthetic technique must be tailored to the type and length of surgery, and a postoperative plan created to reduce the incidence of PONV and provide effective treatments. The importance of the role of polypharmacy is also discussed.

We present a novel coupling scheme consisting of an integrated beam expander, a specifically tailored TiO/sub 2/ antireflection coating, optical index matching gel, and uncoated flat-end single-mode fiber (SMF). This scheme was used to package four-channel semiconductor optical amplifier arrays. Far-field profiles for each discrete amplifier in the array are typically 80 and 150 FWHM, perpendicular and parallel to the junction plane, respectively. The TiO/sub 2/ AR coating overcomes the indices mismatching of fiber glass and InP based device, and reduce optical reflection to 0.002% at 1.55 /spl mu/m. Misalignment tolerance in the l-dB excess loss range, for a discrete channel, is typically 5 /spl mu/m vertically and 8 /spl mu/m laterally. The average coupling loss is 4.3 dB per facet for the devices measured. Fiber coupled small signal gain for the amplifiers is typically 11.6 dB and a saturation output power of 3.0 dBm. The method of characterization and optimization of the TiO/sub 2/ coating is discussed.

Following the introduction of practical work in DNA technology to school science courses using the inexpensive DNA kits produced by Science and Plants for Schools (SAPS) and the National Centre for Biotechnology Education (NCBE), there is a need to expand the limited set of available protocols. This paper describes a computer simulation for schools and colleges which complements the laboratory work with DNA kits. This enables a pupil to predict initial restriction maps which may later be checked by electrophoresis. It outlines the principles of construction of restriction maps from base (or nucleotide) sequence and gel electrophoresis data. Keywords: DNA, Restriction analysis, Mapping

Intraband modulation in semiconductor gain media has recently been shown to provide a wideband nonlinearity which is five orders of magnitude larger than the Kerr non-linearity in silica fiber. We discuss recent work on the application of this nonlinearity to the wavelength conversion function in all optical networks; specifically, carrier wavelength spectral translation by four-wave mixing. In addition to reviewing the current performance of these devices including conversion efficiency, signal-to-noise and a simple system demonstration, we will describe the underlying physics of the ultra-fast four-wave mixing mechanism and its application to TeraHertz spectroscopy of intraband scattering. An overview of wavelength conversion in the context of all-optical networks is provided and competing techniques to four-wave mixing wavelength conversion are also discussed.

Near field holography is a method of using grating photomasks in which the m = -1 and m = 0 diffracted beams of a UV source interfere to form a standing wave pattern. This simple hologram can then be used to expose a grating pattern on a process wafer when held in near- contact. This technique is especially attractive for use in OEICs and PICs when fabrication of the grating masks is accomplished with e-beam lithography and dry etching, since the diffractive properties of the mask can be controlled by the physical parameters of the mask. The grating period on masks made in this way can be precisely controlled to produce arrays of lasers each separated by only a small change in frequency (order 100 GHz) as may be required for WDM applications. We review the phenomenology of fused silica phase grating masks and describe work toward establishing characterization criteria, implementing practical printing methods, improving e-beam precision, and demonstrating laser array performance. We discuss principle issues and progress in each of the technical areas.

We discuss wavelength tuning and its corresponding quantum efficiency modulated by the standing wave effects in a resonant-cavity enhanced (RCE) photodetector. Specific design conditions are made for a thin In/sub 0.53/Ga/sub 0.47/As (900 /spl Aring/) photodetector wafer-fused to a GaAs-AlAs quarter wavelength stacks (QWS). Analytic expressions for the calculation of resonant wavelength and standing wave effects are derived, using a hard mirror concept of fixed phase upon reflection, and are found to agree reasonably well with the exact numerical approach, using a transmission matrix method. We then experimentally demonstrate that wavelength tuning as large as 140 nm and its corresponding quantum efficiency modulated by the standing wave effects are clearly observed in our wafer-fused photodetectors, consistent with the predictions. The external quantum efficiency at 1.3 /spl mu/m wavelength and absorption bandwidth for the wafer-fused RCE photodiodes integrated with an amorphous Si-SiO/sub 2/ dielectric mirror are measured to be 94% and 14 nm, respectively. This technique allows the formation of multichannel photodetectors with high quantum efficiency and small crosstalk, suitable for application to wavelength demultiplexing and high-speed, high-sensitivity optical communication systems. >

The next generation of undersea lightwave systems is likely to take advantage of the nonlinear properties of the transmission fiber by employing optical solitons [1,2]. A critical component will be the transmitter which generates the solitons and encodes the data. Previously, we have reported a monolithic extended-cavity laser, which actively mode-locked, generates solitons [3], An extended-cavity laser integrated with a modulator exhibited multi-peaked pulses due to internal reflections and a corresponding time bandwidth product of 0.8, which would prohibit soliton applications [4], Here, we report the first monolithic semiconductor transmitter which has applications in soliton systems. An extended-cavity laser section generates 8-ps solitons by active mode-locking and data is encoded by means of the integrated modulator at a bit rate of 4.9 Gbit/s. The optical pulses exhibit a time-bandwidth product of 0.30 and the extinction ratio of the monolithically integrated electro-absorption modulator is 20 dB.

We present a new design for a digitally tunable laser using two waveguide grating routers with different free spectral range. For an N-channel device, both the number of required amplifiers and the number of required grating arms scale as the square root of N, resulting in a more compact device than previously demonstrated and better scaleability. Contrary to previously demonstrated devices with a reduced number of amplifiers, all wavelength channels are multiplexed together in one common channel, allowing for a higher output power. Tuning speeds below 10 ns are envisioned. Experimental results are presented.

The U.S. Department of Defense (DOD) is the largest single user of energy in the United States (U.S.) [2], representing 0.8% of the total U.S. energy consumed and 78% of the energy consumed by the Federal government. Approximately 25% of DOD energy use is consumed by its buildings and facilities. The DOD currently has 316,238 buildings across 5429 sites translating to a monetary value of $450B [3]. The Office of the Secretary of Defense (OSD) has published an energy policy to ensure the DOD infrastructure is secure, safe, reliable and efficient [4]. The realization of this OSD energy policy, within the DOD, is being guided by (1) the Energy Policy Act of 2005, (2) Executive Order (EO) 13423, and (3) the Energy Independence and Security Act of 2007, to ensure a 30% energy reduction by 2015. The Policy Act of 2005, as well as EO 13423, has set a minimum contribution of renewable energy from DOD s installations of 5% by fiscal year (FY)2012 and no less than 7.5% beginning FY2013 [5]. Under the Distributed Power Systems for Sustainable Energy project described in this report, United Technologies Research Center (UTRC) in collaboration with the University of Wisconsin Madison (UWM), has demonstrated the key technologies that will enable scalable deployment of distributed power sources and energy storage. These key technologies have been demonstrated in such a way that the distributed power sources would appear as a single stable entity to the electrical grid. The technologies demonstrated as part of this project, when adopted, will provide the infrastructure and controls required for efficient and reliable use of renewable energy sources. These microgrids will provide the largest opportunity for reducing external grid utilization, reducing the environmental impact associated with the use of non-renewable sources, and is an important step toward the required security of energy supply at DOD installations.

A photonic circuit implementing ten frequency reference filters for narrow-channel wavelength division multiplexing (WDM) has been fabricated. A diluted multiquantum-well waveguide structure is shown to yield a very low TE/TM polarization dependence of 1 AA, as well as improved absolute frequency control and reproducibility. A standard deviation in absolute filter wavelength of 3.33 AA is measured on a random set of devices from a 2-in wafer. The ten channels are evenly spaced by 7.2 AA. Such filters can be used to lock tunable lasers to a set of reference frequencies for WDM applications. The demonstrated diluted multiquantum-well waveguide structure with low birefringence and improved absolute wavelength control could potentially be used in other WDM integrated circuits requiring tight wavelength tolerance and polarization insensitivity. >

Details on the design, fabrication and properties of the first interferometric intensity modulators with monolithically integrated optical gain are presented. These guided-wave devices make use of two sets of InP-based quantum well heterostructures that are contained in a single base wafer and individually designed for enhanced electrorefraction and amplification at 1.55 mu m. The unique quantum well electrooptic properties as well as the fabrication techniques and waveguide design issues that determine final device performance are discussed. >

We propose and demonstrate a novel high-speed and wavelength insensitive Y-branch modulator in InGaAsP multiple-quantum-wells that exhibits negligible chirp and is also suitable for achieving controllable chirp. We raise the refractive index on one arm via applied bias and use the unbiased arm as a modulator. As the light switches to the biased arm, the modulated light in the unbiased arm experiences little phase change and therefore exhibits negligible chirp. Tunable chirp may be achieved using a push-pull bias configuration. We demonstrate that our modulator chirp is /spl sim/10 times lower than that of typical electroabsorption modulators.

We demonstrate a novel Y-branch digital switch with a double-etch waveguide structure to greatly enhance the loss and crosstalk performance. The double-etch design increases the coupling between the two tapered Y-branch waveguides, which allows for efficient switching while decreasing the radiation loss that arises from the branching angle. This combined advantage also allows us to reduce the switch length, which in turn results in an efficient high-speed design. The measured crosstalk and loss are -19 and 3 dB, respectively, for a 3-mm-long switch. Further crosstalk reduction is expected from the simulation of a more optimized design.

RATIONALE: The tachykinins substance P and neurokinin A (NKA) are implicated in the pathophysiology of asthma. Objective: We tested the safety, tolerability, and pharmacologic and biological efficacy of a tachykinin NK(1)/NK(2) receptor antagonist, AVE5883, in patients with asthma in two double-blind, placebo-controlled crossover studies. METHODS: The pharmacologic efficacy of a single inhaled dose (4.8 mg) of AVE5883 was tested against inhaled NKA in 20 patients with asthma. Subsequently, we studied the biological efficacy of the pharmacologically effective dose on inhaled allergen in a multiple-dose trial (4.8 mg three times per day, 9 d) in 12 patients with asthma with dual responses to inhaled house dust mite. On Day 8, an allergen challenge was conducted, and airway response was measured by FEV(1) until 9 hours postallergen. Exhaled NO, provocative concentration of methacholine bromide causing a 20% fall in FEV(1), and induced sputum were performed on Days 1, 7, and 9. RESULTS: AVE5883 had a bad taste, and transient bronchospasm occurred in some subjects. A single inhaled dose shifted the dose response to NKA by 1.2 doubling doses. Pretreatment with multiple doses of AVE5883 enhanced the allergen-induced early and late airway responses. There were no significant differences in the allergen-induced changes in exhaled NO, provocative concentration of methacholine bromide causing a 20% fall in FEV(1), and sputum cell differentials between placebo and AVE5883. CONCLUSIONS: Despite its demonstrated pharmacologic activity against inhaled NKA, multiple doses of AVE5883 increased the allergen-induced airway responses without affecting markers of airway hyperresponsiveness and airway inflammation. Our data question the prominent role of neurogenic inflammation in asthma and, consequently, the therapeutic potential of dual tachykinin antagonists

Objective: To evaluate immune responses to neoantigen and recall antigens in healthy subjects treated with teriflunomide. Methods: This was a randomized, double-blind, placebo-controlled study. Subjects received oral teriflunomide (70 mg once daily for 5 days followed by 14 mg once daily for 25 days) or placebo for 30 days. Antibody responses were evaluated following rabies vaccination (neoantigen) applied at days 5, 12, and 31 of the treatment period. Occurrence of delayed-type hypersensitivity (DTH) to Candida albicans, Trichophyton, and tuberculin (recall antigens) was assessed before and at the end of treatment to investigate cellular memory response. Safety and pharmacokinetics were evaluated. Results: Forty-six randomized subjects were treated (teriflunomide, n = 23; placebo, n = 23) and completed the rabies vaccination. Geometric mean titers for rabies antibodies were lower with teriflunomide at days 31 and 38 than with placebo. However, all subjects achieved sufficient seroprotection following rabies vaccination (titers well above the 0.5 IU/mL threshold). Overall, the DTH response to recall antigens in the teriflunomide group did not notably differ from responses in the placebo group. Conclusions: Following vaccination, geometric mean titers for rabies antibodies were lower with teriflunomide than with placebo. However, teriflunomide did not limit the ability to achieve seroprotective titers against this neoantigen. Evaluation of DTH showed that teriflunomide had no adverse impact on the cellular memory response to recall antigens. Classification of evidence: This study provides Class II evidence that in normal subjects treated with teriflunomide, antibody titer responses to rabies vaccination are lower than with placebo but sufficient for seroprotection.

An interferometric wavelength converter with preamplifiers for both the signal input and the continuous-wave probe input is presented. The dynamic range of the device is enhanced: penalty-free conversion is demonstrated at 2.5 Gb/s for input powers ranging from -6 to +4 dBm. Transmission of the converted signal over 480 km of standard fiber shows penalty improvement relative to the unconverted, information-limited signal.

Reconfigurable optoelectronic wavelength conversion to 11 100-GHz spaced wavelengths is achieved using a wavelength selectable laser array with an integrated electroabsorption (EA) modulator at a bit rate of 2.5 Gb/s. Wide dynamic range at the input from -24.2 to -6.5 dBm is achieved and uniform back-to-back transmission performance is measured for all wavelengths.

A polarization-insensitive InP-based p-i-n multiple-quantum-well switch is demonstrated for the first time. Polarization-insensitive switching and loss are achieved. Crosstalk and loss measurements across a wavelength range of 20 nm centered at 1.55 /spl mu/m are reported. A crosstalk of better than -13 dB is achieved for both TE and TM polarizations across the 1.54-1.56-/spl mu/m wavelength range with a switching voltage of -7 V. A low on-chip loss of less than 3 dB is achieved for both TE and TM across the above wavelength range, with a compact switch structure which is 3 mm long.

The first interferometric wavelength converter with an integrated continuous-wave (CW) probe source is presented. The two-port device operates independent of polarization for a broad range of input wavelengths. The input dynamic range is enhanced by an integrated input preamplifier. Input powers as low as -5.4 dBm in the fiber are converted with penalties as low as 0.6 dB at a bit rate of 2.5 Gb/s. The device is shown to operate with the same low penalty for same-wavelength operation as well. The chirp parameter /spl alpha/ is measured to be 2 for wavelength conversion. No chirp is added to the input signal for same-wavelength operation.

Reconfigurable channel drop in a wavelength-division multiplexed system is demonstrated using a packaged semiconductor amplifier/filter. The filter is electrically tunable over 9.0 nm with a 0.9-nm width and is used with an optical circulator to demultiplex three 5.0-Gb/s WDM channels spaced by 2.25 nm. A receiver sensitivity improvement and low optical crosstalk is observed over a dynamic range of nearly 10 dB.

We report on an efficient method for suppressing stimulated Brillouin scattering (SBS) with negligible residual amplitude modulation (AM) using the temperature tunable properties of a semiconductor laser diode. We demonstrate an effective threshold of 23.4 dBm by applying a 16 V/sub pp/, 5 kHz sinusoid to a thin-film resistor on top of the laser diode. The residual AM is measured to be only 1.2/spl middot/10/sup -4/.

Active mode-locking of a broadly tunable monolithic semiconductor laser based on a grating assisted vertical coupler filter resulted in 10 - 12 ps pulses at a repetition rate of 15.8 GHz. Mode-locking was achieved at discrete wavelengths from 1544.5 nm to 1564.7 nm.

Boron-doped diamond electrodes have many possibilities for electroanalytical and electrosynthetic application because of their stability and range. However, their combination of semiconductive origin, nearly metallic resistive characteristics when heavily doped, and surface inertness make the understanding of electron transfer at these materials complex. The transition from reversible behavior, with a wide range of outer sphere redox couples with potentials positive of about -0.5 V vs. SCE, to extremely slow kinetics, with systems such as the halogen/halide couples, requires placing all the above properties in context. Experimental data pertaining to these issues and speculation concerning the controlling factors are discussed.

A 1.3-/spl mu/m Fabry-Perot laser with a directional coupler power tap inside the laser cavity, used for diverting optical power to an integrated waveguide monitoring photodetector is demonstrated. The monitoring detector provides photocurrent which is linear with the front facet output power, with responsivity as high as 0.37 mA/mW, depending on the length of the directional coupler coupling region.

An 8-channel DWDM multiplexer with per-channel amplification is demonstrated. 10 dB, 3 dB, and 0 dB fiber-to-fiber gain is achieved using lensed fiber, cleaved fiber, and cleaved fiber array respectively. BER performance is also presented.

We demonstrate a long-wavelength detector structure using an undercut mesa and an air-bridged coplanar metal waveguide to significantly reduce both the diode RC constant and the parasitic capacitance. Record electrical bandwidths of 120 GHz are demonstrated for long-wavelength photodetectors.

We propose and demonstrate a simple, potentially low-cost, photonic integrated circuit that can operate as a transceiver in a ping-pong optical data-link configuration. The device is designed for uncooled operation, with a gain section, a detector, and a beam expander inside a Fabry-Perot cavity. The detector has a 1.4 /spl mu/m quaternary layer with a broad spectral responsivity range extending to 33 nm higher than the lasing wavelength of the device. The transmitter can provide 8 dBm inside a single-mode fiber, and the beam expander relaxes the alignment tolerance to a single-mode fiber.

Wavelength conversion using semiconductor optical amplifiers monolithically integrated in a three-part Mach-Zehnder configuration is achieved for data rates of 1 and 2.5 Gb/s. The three-port configuration allows efficient use of pump signal power, as well as counter-propagation of pump and converted signals, eliminating the need for a filter. Operation of the device at 5 Gb/s in a two-port configuration is also achieved. Dynamic extinction ratios larger than 13 dB, as well as both data-inverting and noninverting operation are demonstrated. >

A novel optical translator that can perform 3R-regeneration and wavelength conversion of high-speed return-to-zero signals is demonstrated at 20 Gbit/s. Efficient retiming and bit-error-rate performance is measured using a Mach-Zehnder interferometer with integrated semiconductor optical amplifiers.

We demonstrate a photonic circuit with an optical preamplifier, a WDM filter and a fast photodetector integrated on the same chip. The passive integrated filter is formed by an aspheric waveguide lens and a planar Bragg grating. This arrangements yields narrow filter response (8 /spl Aring/ width at -3 dB is demonstrated) and high rejection ratio of 24 dB. The optical preamplifier consisting of strained multi-quantum well layers provides sufficient amplification to overcome the passive losses. Response curves demonstrate net on-chip gain with low ripple. >

Using tensile‐strained InGaAs/InGaAsP multiple quantum well material to increase the gain bandwidth, we demonstrate a tuning range of 74.4 nm with sidemode‐suppression ratio of ≳25 dB and as high as 34 dB in a broadly tunable vertical‐coupler filtered laser at 1.55 μm. Due to its wide gain bandwidth and significant gain‐peak shift to shorter wavelengths with gain current increase, the tensile‐strained quantum well material is well suited for broadly tunable lasers.

We demonstrate a polarization‐insensitive optical bandpass filter in indium phosphide (InP) with a 3 dB bandwidth of 1.5 nm at a center wavelength of 1.498 μm. The 5‐mm‐long filter is based on a grating‐assisted vertical directional coupler and features a novel double‐periodic coupling grating.

A novel monolithic semiconductor laser is demonstrated. The optical cavity comprises a 1/spl times/N waveguide grating multiplexer connected to N optical amplifiers. By driving a specific output port, laser oscillation is obtained at the wavelength determined by the wavelength path through the multiplexer. Such a laser is very useful for WDM systems because it is capable of producing a comb of precisely spaced frequencies. >

Selective implantation of 140 keV Co ions into self-supporting diamond films converts the surface into a conductive region at which redox electron transfer and metal deposition have been accomplished. Simple masking allows precise definition of the area to be plated within the insulating diamond matrix. Formation and electrochemical characterization of a rotating disk electrode in this manner are demonstrated.

We demonstrate electrically injected InGaAsP (1.3 μm) vertical cavity lasers (VCLs) fabricated on GaAs substrates and employing GaAs/AlAs mirrors. The technique of wafer fusion allows for integration of GaAs/AlAs mirrors with InP double heterostructures without degradation of device performance, despite a 3.7% lattice mismatch between the wafers. The wafer fused VCLs have the lowest threshold current (9 mA) and lowest threshold current density (9.5 kA/cm2) and the highest characteristic temperature (T0=67 K) reported to date of any room‐temperature long wavelength VCL.

Four-wave mixing in traveling-wave amplifiers (TWA's), when used for wavelength conversion, has several advantages. Owing to their traveling-wave operation, these devices offer the potential for very high speed operation as well as continuous tuning of the input and output wavelengths. In addition, since the converted signal is the phase-conjugate replica of the input signal, the conversion is transparent to the modulation format, and provides the possibility for fiber-dispersion-compensation in lightwave communication systems. In this paper, we present measurements of wavelength conversion efficiencies in TWA's for /spl Delta//spl lambda/-shifts as large as 27 nm. We show that wavelength up-conversion is less efficient than down-conversion and show that the effect results from phase interference between the interband and intraband mechanisms causing four-wave mixing. >

We demonstrate lasing in InGaAsP (1.3 /spl mu/m) vertical cavity lasers employing GaAs/AlAs mirrors on a GaAs substrate. The lasers operate pulsed at 300 K with a threshold current of 9 mA and they operate continuous wave at temperatures as high as 230 K. >

Seven packaged wavelength selectable laser arrays were tested and found to have average chirp parameter of 0.18 /spl Aring/ under 2.5 Gb/Sec modulation. Temperature tuning necessary to reach a standard WDM wavelength for any laser on any of the packages was /spl les/5.2/spl deg/C.

Summary form only given. We demonstrate a novel modulation scheme in which both data-encoding and pulse generation are achieved using a single integrated semiconductor laser/modulator. Data-encoded, near-transform limited 66 ps pulses are obtained at 2.5 Gbit/s and BER performance is reported.

Wavelength conversion is recognized as an important function in future fiber networks employing wavelength division multiplexing. The authors have recently demonstrated broad-band wavelength conversion over spans as large as 27 nm. Their approach uses ultra-fast four-wave mixing dynamics associated with intraband relaxation mechanisms in semiconductor traveling-wave amplifiers (TWA's). In the paper the authors present new results showing conversion over wavelength spans as large as 65 nm. This surpasses the previous record by over a factor of two. Of equal importance, they also verify experimentally their previous theoretical prediction that wavelength conversion efficiency varies as the cube of TWA single pass gain. In the course of our previous work, we have shown that the theoretical efficiency, η, of this process can be expressed by the simple relation: η = 3G + 2P + R(Δ⋋) where η is the ratio in dB of the converted signal output power to the signal input power and G is the single pass TWA optical gain. A crucial point is the presence of 3G in this expression - essentially, the wavelength converter uses the available TWA optimal gain three times. We verified this expression using an experimental setup similar to that described in. Tunable, single-frequency, erbium fiber ring lasers were used as pump and signal sources and TWA devices used contained tensile-strained mutli-quantum well active layers described in. Figure 1 shows conversion efficiency data plotted versus single-pass saturated optical gain. The pump power was -5.2 dBm and the signal power was -11.3 dBm. The measured slope of 3.18 confirms the cubic dependence of efficiency on single pass gain.