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Nonlinear propagation in periodic media has been studied for decades, yielding demonstrations of numerous phenomena including strong temporal compression and slow light generation. Gap solitons, that propagate at frequencies inside the stopband, have been observed in optical fibres but have been elusive in photonic chips. In this manuscript, we investigate nonlinear pulse propagation in a chip-based nonlinear Bragg grating at frequencies inside the stopband and observe clear, unequivocal signatures of gap soliton propagation, including slow light, intensity-dependent transmission, intensity-dependent temporal delay and gap soliton compression. Our experiments which are performed in an on-chip ultra-silicon-rich nitride (USRN) Bragg grating with picosecond time scales, reveal slow light group velocity reduction to 35%–40% of the speed of light in vacuum, change in the temporal delay of 7 ps at low peak powers between 15.7 W–36.6 W, which is accompanied by up to 2.7× temporal compression of input pulses. Theoretical calculations using the nonlinear coupled mode equations confirm the observations of intensity-dependent temporal delay. Of fundamental importance, this demonstration opens up on-chip platforms for novel experimental studies of gap solitons as the basis of all-optical buffers, delay lines and optical storage.

Purpose: To report a case of orbital apex syndrome and central retinal vein occlusion after blow-out fracture repair.Case summary: A 22-year-old man who underwent emergency re-operation in a department of plastic surgery due to pain, decreased visual acuity, and ophthalmoplegia in all direction after orbital blow-out fracture repair was referred to ophthalmologist on postoperative day 2 and there was no improvement in symptoms. He showed severe complications, including optic neuropathy and ophthalmoplegia in all direction, central retinal vein occlusion, and outer retinal disruption caused by orbital apex hemorrhage. Although we were concerned that it was too late, we started high dose steroid intravenous pulse treatment and the visual acuity, ophthalmoplegia, and retinal findings were improved. However, the optic atrophy and visual field defect did not.Conclusions: After a complicated blow-out fracture repair in other department, if a patient shows severely decreased visual acuity or ocular movement limitation, a thorough and immediate ophthalmologic examination is recommended. During ophthalmologic examination, meticulous examination of the entire eye, including the retina, is required, in addition to general orbital complications. A relatively good prognosis can be expected through accurate cause analysis and appropriate treatment for the confirmed abnormal findings.

The generation of optical pulse trains from continuous-wave light has attracted growing attention in recent years because it provides a simple way to obtain high repetition rate ultrashort pulses. While pulse generation has been extensively demonstrated in optical fibers, pulse train generation from weak, continuous wave light in photonic chips has posed significant challenges because of the short interaction length and therefore difficulty in acquiring sufficient new frequency content, and/or absence of the appropriate dispersion environment. In this manuscript, we report the pulse train generation of a low continuous-wave signal to 18 ps, by leveraging cross-phase modulation induced by co-propagating pump pulses with a peak power of 3.7 W in an ultra-silicon-rich nitride grating. The pulse train generation dynamics are documented both experimentally and theoretically to arise from cross-phase modulation-induced generation of new spectral content, and dispersive re-phasing. This is a new approach in which picosecond pulse generation may be achieved from low power, continuous-wave light.

An 11-year-old intact female mixed breed dog was presented with abdominal distention and elevated hepatic enzyme levels. Computed tomography revealed a multicystic hepatic mass at the left medial lobe adjacent to the diaphragm and caudal vena cava. The mass was surgically removed with partial hepatectomy, but it could not be removed completely because of adhesion to the diaphragm. The tissue was submitted for histopathologic evaluation, and the patient was diagnosed with stage IIIA combined hepatocellular-cholangiocarcinoma (cHCC-CC). Considering the residual tumor tissue from incomplete surgical excision, adjuvant chemotherapy was recommended. Tumor tissue obtained from the patient was assessed using an anticancer drug response prediction test, and the results showed that toceranib phosphate was the most effective chemotherapeutic agent for this patient. Toceranib was initiated (3.1 mg/kg, PO, q48 h), and routine adverse effect assessment, including systemic blood pressure measurement, complete blood count, serum biochemical evaluations, and urinalysis were performed at two-week intervals for the first 2 months and every 2 months thereafter. Radiography and ultrasonography were conducted at one-month intervals for the first two months and then every 2 months subsequently. Concurrent hyperadrenocorticism was managed with trilostane (1 to 5 mg/kg, PO, q12h). The patient showed no critical adverse effects of chemotherapy, obvious recurrence, or metastasis. The response to toceranib was assessed as a partial response, and the patient is still alive over 23 months after tumor excision. This is the first case report describing chemotherapy for a dog with cHCC-CC.

We demonstrate a complementary metal–oxide–semiconductor (CMOS)-compatible optical parametric Bragg amplifier on an ultra-silicon-rich nitride chip. The amplifier design incorporates advantageous group index properties in a nonlinear Bragg grating to circumvent phase matching limitations arising from the bulk material and waveguide dispersion. The grating structure further augments the effective nonlinear parameter of 800 W−1/m, considerably lowering the power required for the observation of strong parametric gain. On/off optical parametric gain of 20 dB is achieved using a low peak power of 1.6 W, in good agreement with numerical calculations. This represents a 7 dB improvement in the parametric gain compared to the absence of grating enhancement which is attributed to the Bragg grating induced superior phase matching.

A 12-year-old, 3.5-kg, intact female dog was presented with polyuria, polydipsia, and a pendulous abdomen. Laboratory examinations showed elevated hepatobiliary enzyme levels and neutrophilic leukocytosis. The adrenocorticotropic hormone stimulation test confirmed hyperadrenocorticism (HAC). Trilostane therapy managed the clinical condition and cortisol concentration. However, lymphocytosis and nonregenerative anemia developed after HAC remission. Bone marrow aspiration analysis revealed a lymphoproliferative disorder with a clonal T-cell population. Accordingly, the patient was diagnosed with T-cell chronic lymphocytic leukemia (CLL) and concurrent HAC. Thereafter, chemotherapy was initiated, which improved the lymphocytosis. However, euthanasia was performed because of worsening quality of life at 45 weeks after the first presentation. These results suggested that CLL could be masked by excessive endogenous cortisol and discovered after HAC remission.

We experimentally demonstrate picosecond pulse generation from a low-power continuous-wave signal, generating 18ps pulses, by leveraging cross-phase modulation of pump pulses with a low peak power of 3.7 W in an ultra-silicon-rich nitride Bragg grating.

A 1.2-octave-spanning supercontinuum generation is demonstrated in a 3-mm-long ultra-silicon-rich-nitride waveguide using 17pJ, 500fs pulses. The generated supercontinuum possesses a spectral coherence (|g12|) exceeding 0.94 on average across the measured wavelength range.

We demonstrates the first optical prametric amplification using nonlinear Bragg grating where enhanced phase matching is enabled by utilizing the rapid increase and decrease in effective index near the stopband. An on/off parametric gain of 20dB is achieved in a 3-mm ultra-silicon rich nitride Bragg grating at a low peak power of 1.6W.

Bragg-soliton dynamics in a 2-stage ultra-silicon-rich-nitride (USRN) chip-based device, consisting of a cladding-apodized modulated Bragg grating (CMBG) stage and a USRN channel waveguide stage, is studied and optimized for enhanced supercontinuum generation. We observe that the enhancement is strongly dependent on the Bragg-soliton effect temporal compression developing in the CMBG stage, which is linked to both device and input pulse parameters. With the optimal parameter combination, a supercontinuum spanning 610 nm at the −30 dB level is experimentally demonstrated in the 2-stage USRN device, representing a 5× enhancement compared to that in a reference waveguide. Good agreement is obtained between the experimentally measured supercontinuum and simulations based on the generalized nonlinear Schrödinger equation and is consistent with design rules based on Bragg soliton compression. This device provides an encouraging path to generate supercontinuum in compact chip-based platforms, which does not need ultrashort, femtosecond scale pulses, greatly relaxing the pulse width and pulse power requirement.

A 16-year-old spayed female Pomeranian dog was presented to the hospital with an acute onset of pain and non-weight-bearing lameness in the right forelimb. On physical examination, knuckling, coolness, pain, and cyanosis were observed in the affected forelimb. Peripheral blood glucose concentration and body surface temperature differed between the right and left forelimbs. Hypercoagulable thromboelastographic results and increased D-dimer levels were suggestive of thrombus. Accordingly, recombinant tissue plasminogen activator (rtPA) was administered intravenously. Prompt clinical improvements (including restored warmth of the affected limb) occurred, and rtPA was discontinued after two shots administered 2 h apart owing to concerns of bleeding side effects. The dog was discharged 6 days after admission, and outpatient treatment with clopidogrel was continued for the prevention of re-thrombosis. Following patient stabilization, further examinations for underlying diseases of hypercoagulability were conducted; hyperadrenocorticism (HAC) was diagnosed, and oral trilostane therapy was thus administered. Eight weeks later, the patient regained normal mobility. Finally, in the present canine patient with arterial thrombosis, thrombolysis with rtPA successfully improved clinical symptoms and the following administration of clopidogrel inhibited the formation of additional thrombus.

Three-dimensional monolithically integrated polymer microtoroid resonator-waveguide system and nested-double-spiral waveguides are fabricated and characterized. Transmission of 30Gb/s non-return-to-zero data and 28Gb/s pulse amplitude modulation-4 data is demonstrated.

Topological boundary states are well localized eigenstates at the boundary between two different bulk topologies. As long as bulk topology is preserved, the topological boundary mode will endure. Here, we report topological nonlinear parametric amplification of light in a dimerized coupled waveguide system based on the Su-Schrieffer-Heeger model with a domain wall. The good linear transmission properties of the topological waveguide arising from the strong localization of light to the topological boundary is demonstrated through successful high-speed transmission of 30 Gb/s non-return-to-zero and 56 Gb/s pulse amplitude 4-level data. The strong localization of a co-propagating pump and probe to the boundary waveguide is harnessed for efficient, low power optical parametric amplification and wavelength conversion. A nonlinear tuning mechanism is shown to induce chiral symmetry breaking in the topological waveguide, demonstrating a pathway in which Kerr nonlinearities may be applied to tune the topological boundary mode and control the transition to bulk states.

The dispersive nonlinear refractive index of ultra-silicon-rich nitride, and its two-photon and three-photon absorption coefficients are measured in the wavelength range between 0.8 µm–1.6 µm, covering the O- to L – telecommunications bands. In the two-photon absorption range, the measured nonlinear coefficients are compared to theoretically calculated values with a simple parabolic band structure. Two-photon absorption is observed to exist only at wavelengths lower than 1.2 μm. The criterion for all-optical switching through the material is investigated and it is shown that ultra-silicon-rich nitride is a good material in the three-photon absorption region, which spans the entire O- to L- telecommunications bands.

Silicon carbide (SiC) is considered a promising platform for linear and nonlinear photonics due to its large band gap, large refractive index, low thermo-optic coefficient, large Kerr nonlinearity,...

Optical pulses are fundamentally defined by their temporal and spectral properties. The ability to control pulse properties allows practitioners to efficiently leverage them for advanced metrology, high speed optical communications and attosecond science. Here, we report 11× temporal compression of 5.8 ps pulses to 0.55 ps using a low power of 13.3 W. The result is accompanied by a significant increase in the pulse peak power by 9.4×. These results represent the strongest temporal compression demonstrated to date on a complementary metal–oxide–semiconductor (CMOS) chip. In addition, we report the first demonstration of on-chip spectral compression, 3.0× spectral compression of 480 fs pulses, importantly while preserving the pulse energy. The strong compression achieved at low powers harnesses advanced on-chip device design, and the strong nonlinear properties of backend-CMOS compatible ultra-silicon-rich nitride, which possesses absence of two-photon absorption and 500× larger nonlinear parameter than in stoichiometric silicon nitride waveguides. The demonstrated work introduces an important new paradigm for spectro-temporal compression of optical pulses toward turn-key, on-chip integrated systems for all-optical pulse control.

Nonlinear integrated optics leveraging platforms with high nonlinear figure of merit offer energy efficient optical signal processing capabilities. Over the last five years, CMOS-compatible ultra-silico-rich nitride (USRN) has emerged as a promising platform on which to implement various nonlinear optics functions. Bandgap engineered to maximize the Kerr nonlinearity while maintaining two-photon absorption free behavior at telecommunications wavelengths, USRN possesses a nonlinear refractive index that is 100× larger than that in stoichiometric silicon nitride. In this article, we review the recent progress made in USRN-based nonlinear integrated optics devices. The impacts it has made spanning from high gain optical parametric amplification and observations of soliton effects in photonic waveguides and photonic crystal waveguide structures will be discussed. Finally, we assess the future outlook of CMOS-compatible USRN-based nonlinear optics.

Strong temporal compression in an integrated ultra-silicon-rich nitride temporal compressor consisting of separate nonlinear and anomalously dispersive stages is demonstrated. 11× compression of 5.8ps pulses at a low input peak power of 13.3W and 9.4× increase in the pulse peak power is achieved.

Integrated photonic nanostructures provide powerful degrees of design freedom for the engineering of light confinement and advanced lightwave manipulation functions. The ability to tailor field profiles in these on-chip devices allows enhanced light-matter interaction, strong modal confinement and the ability to engineer dispersion. Here, we present recent developments in photonic integrated circuits towards the generation of solitons, amplification, and optical waveform manipulation. By harnessing CMOS platforms with a high nonlinear figure of merit, the existence of on-chip Bragg solitons, Bragg soliton fission and solitons in photonic waveguides are experimentally observed. These demonstrations are made possible by 1,000X larger dispersion close to the band edge in on-chip Bragg gratings, an effect that arises from the interaction of forward and backward propagating fields. In addition, efficient parametric processes facilitate wavelength conversion of light and high gain amplification of signals. These efficient nonlinear mechanisms provide a possible pathway in which to realize new approaches to efficiently manipulate optical waveforms.

Parametric wavelength conversion of 30Gbps Non-Return-Zero data using degenerate four wave mixing was performed in ultra-silicon-rich nitride waveguides. A power penalty of 1.2dB was achieved at a bit error rate of 10-4.

Nonlinear CMOS Photonics allows for seamless integration with CMOS electronics and ease of manufacturability. We discus developments in USRN-based nonlinear optics. We demonstrate 8.7 soliton-effect compression in USRN waveguides, on-chip Bragg-soliton compression and fission.

Temperature tuning of spectral broadening induced by a nonlinear grating is experimentally demonstrated. The bandwidth is observed to decrease as temperature increases, corresponding to a red-shift in the high dispersion region of the Bragg grating.

Nonlinear properties of GeSe2-As2Se3-PbSe are studied using z-scan measurements from 2.5μm–5.5μm. The largest nonlinear refractive index is observed at 2.8μm, corresponding to the two-photon edge. A sub-peak at 4.6μm arises from mid-gap defect states.

An integrated polymer microtoroid resonator system fabricated using single-step, two-photon polymerization laser lithography is reported. The integrated microtoroid-waveguide system includes an integrated coupling waveguide for ease of optical coupling and has a quality factor of 16,000. We further demonstrate a nested double-spiral waveguide that allows higher spatial density of data, akin to a macroscopic form of space-division multiplexing. Experimental characterization reveals good transmission properties in the double-spiral waveguide device. In addition, the waveguides are demonstrated to support 30 Gb/s nonreturn-to-zero and 28 Gb/s pulse amplitude modulation 4 high-speed data.

An on-chip Coarse wavelength Division Multiplexing (CWDM) has been designed, fabricated and experimentally measured, yielding 9 multiplexed wavelength channels spanning S+C+L band. The average channel crosstalk is −25 dB. All channels cover the CWDM central wavelengths stipulated by ITU standard.

Nonlinear phenomena at the 1550nm wavelength are studied in ultra-silicon-rich nitride devices. Photonic crystals in one are demonstrated to introduce 1000x enhancement in the group velocity dispersion properties and a 40x increase in the nonlinear parameter. The large Kerr nonlinearity and negligible two-photon absorption allow strong nonlinear effects including 42.5dB optical parametric gain and Bragg soliton based temporal compression to be demonstrated.

We demonstrate pulse compression using ultra-silicon-rich nitride grating devices. Frequency chirp from a waveguide is temporally synchronized by a dispersive grating to achieve temporal compression by a factor of 4.3. When reversed, spectral compression of 2.3× is achieved.

The nonlinear optical properties of GeSbS chalcogenide glass are characterized in the wavelength range from 1.1-5.5μm. High order multi-photon up to the 11th order, multiphoton induced photoluminescence and nonlinear refractive indices are experimentally measured.

We demonstrate the optical pulse compression of 2ps laser down to 230fs pulse resulting in 8.7 times compressed using a USRN waveguide. The process is facilitated by high-order soliton formation arising from a large nonlinear parameter and anomalous group velocity dispersion.

Nonlinear optical properties of ultra-silicon-rich nitride are investigated. The nonlinear refractive index and two-photo and three-photon absorption coefficients are measured in the range of 0.8pm-1.6pm covering the C- and L-bands.

Silicon carbide ring resonator is demonstrated with intrinsic Q-factor of 160,000. Waveguide with nonlinear parameter 40W-1/m is demonstrated. Material Kerr nonlinearity is measured to be 4.8 ×10−14cm2/W and three photon absorption coefficient is around 0.01cm3/GW2.

Correlated photon pair generation is demonstrated using ultra-silicon-rich nitride waveguides. Waveguides with a length of 10 mm, nonlinear parameter of 530 W−1/m and anomalous dispersion are used to achieve spontaneous four-wave mixing. A generated coincidence rate of 2.40 × 105 counts per second is achieved, and derived from a measured coincidence rate of ∼ 1 counts per second at the maximum coupled power of 5 mW, in line with the expected quadratic dependence of spontaneous four-wave mixing efficiency on power. Utilizing picosecond pulses as the pump, we achieve a measured coincidence rate of up to 1.8 counts per second, resulting in a generated coincidence rate of 2.20 × 10−2 counts per pulse at the maximum peak power of 8.33 W. 2.3 times larger coincidence-to-accidental ratio is also obtained using a pulsed pump compared to that achieved with a continuous-wave pump. Further enhancements via the use of ring resonators may be adopted.

Correlated single photons provide a means to drive applications such as quantum computing and quantum communications. Correlated single photons can be generated via parametric down conversion in second–order nonlinear media or spontaneous four–wave mixing in third–order nonlinear media. In particular, complementary metal–oxide–semiconductor (CMOS) technology allows for seamless integration with electronics, providing the potential for a completely on-chip solution for quantum information processing. Ultra–silicon–rich nitride platform is a backend CMOS compatible platform, that has already been used to obtain high gain optical parametric amplification, wideband supercontinuum and enhanced nonlinearity in photonic crystal waveguides due to its large nonlinearity. In this work, we demonstrate correlated photon pair generation based on spontaneous four–wave mixing using ultra-silicon-rich nitride waveguides for the application in CMOS–based optical quantum technologies. A CW pump at a wavelength of 1555.747nm amplified using an EDFA is filtered through five wavelength division multiplexers (WDM) with a bandwidth of 1.2nm, providing 175dB suppression of EDFA induced pump sideband noise. The filtered quasi–TE pump, adjusted using a fiber polarization controller, is coupled into an ultra–silicon–rich nitride waveguide using a lensed fiber. A SiO2 cladded waveguide with a width of 550nm and height of 300nm possesses a high nonlinear parameter of 530W^-1/m with anomalous dispersion necessary for spontaneous four-wave mixing. The waveguide output is coupled into a lensed fiber and 7 cascaded WDMs are used to provide 245dB of residual pump filtration. The pump–suppressed output is spectrally separated into signal/idler part using WDMs. We refer to lower (higher) frequency photon as the signal (idler). The spontaneously generated signal and idler photons are filtered using cascaded tunable band pass filters (OTF) centered at 1571.24nm and cascaded WDMs centered at 1540.56nm, respectively. The bandwidth of the tunable OTF and WDM is 0.5nm and 1.2nm, therefore the correlated signal/idler photons are observed within the bandwidth window of 0.5nm induced by the OTF. The signal and idler photons are measured using InGaAs/InP avalanche photodetectors. The time correlation between signal and idler photons is obtained using a time interval analyzer with a detection efficiency of 20% and dead time of 15μs.The time bin is set to 81ps and the photon collection time is 240s. The coincidence peak is located ~11ns in the time–bin histogram due to the optical-path difference between the tunable OTF and WDM at respective signal and idler sides. The experimental raw coincidence counts (Hz), calculated by subtracting the accidental rate from the coincidence peak, show a quadratic increase with respect to coupled pump power. At the maximum coupled power of 5mW, the raw coincidence count is ~1Hz. We achieve a raw coincidence–to–accidental ratio (CAR) of up to 3. Therefore, we succeeded to observe correlated photon pair generation based on spontaneous four–wave mixing using the ultra–silicon–rich-nitride waveguide as a CMOS compatible platform, for future applications in quantum technologies.

Four–wave mixing (FWM) serves as the physical basis for various nonlinear phenomena including wavelength conversion, parametric amplification, and frequency combs. FWM on a chip has been implemented using CMOS platforms, chalcogenide glasses and III–V materials. On-chip, waveguide based stimulated FWM techniques have been mostly demonstrated using a coherent pump and coherent signal to focus on broadband spectral tuning for operation in high–speed and multi–channel wavelength division multiplexing network. Though FWM using incoherent light has the potential to provide large optical conversion efficiency, such demonstrations remain largely confined to fiber–experiments and involved narrow–band signals/idlers. Furthermore, the FWM based on a pulsed laser and a broadband incoherent source has yet to be implemented. In this work, we demonstrate integrated ultra–silicon–rich nitride parametric converters that perform wavelength conversion of a broadband incoherent source with a bandwidth of ~100nm at the -20dB level. A 500fs pulsed pump is combined with an incoherent superluminescent diode (SLD) as the signal and parametric gains between 12dB – 27dB is demonstrated as well as cascaded FWM. A 500fs pulsed laser centered at 1.555μm and an incoherent SLD with a 20dB bandwidth spanning from 1.6 – 1.7μm are used as the pump and signal respectively. The pump and signal are combined with a wavelength division multiplexer and coupled into an ultra–silicon–rich nitride waveguide with 10mm length, 700nm width and 400nm height. The waveguide is designed to have a larger nonlinear parameter of 330W^-1/m while possessing anomalous dispersion of -0.92ps^2/m, necessary for phase matched parametric conversion. At a coupled peak power of 4.6W, an idler spanning from 1.43 – 1.52μm at the -20dB level is generated. At a maximum input signal power of 0.71mW, a second idler appears at the blue side of the first generated idler because of cascaded FWM induced between pump of 1.555μm and the first idler peak of 1.48μm. At a coupled peak power of 2.8W, an idler spanning from 1.46 to 1.52μm is generated. The experimental idler bandwidth agrees well with the calculation based on degenerate FWM phase–matching condition. The broadened idler powers are calculated by integrating the energy of each signal and idler with respect to wavelength to obtain optical conversion efficiencies. The integrated idler power is 3.4dBm and 13.4dBm, corresponding to idler parametric gain of 12dB and 18dB respectively at a coupled peak power of 2.8 and 4.6W, respectively. The application of the SLD signal to a supercontinuum that is generated at a coupled peak power of 26W spectrally spanning 1.1 – 1.7μm is observed to generate an idler power of 14dBm within the wavelength range of 1.18 – 1.42μm as well as an idler conversion efficiency/gain of 27dB. Therefore, we achieved broadband wavelength conversion based on stimulated FWM using a pulsed pump and broadband incoherent signal that facilitate the spectrum spanning from 100nm, sufficient to cover parts of the E– and S–bands an representing large conversion efficiency and parametric gains of 12dB – 27dB.

Optical parametric amplifiers rely on the high Kerr nonlinearities and low two-photon absorption (TPA) to achieve large optical amplification. The high Kerr nonlinearity enables efficient energy transfer from the optical pump to the signal. On the other hand, the TPA process competes with the amplification process, and thus should be eliminated. Through Miller’s rule and Kramers-Kronig relations, it is known that the material’s Kerr nonlinearity scales inversely proportional to the band-gap, while the TPA process occurs when the photon energy is larger than the band-gap energy and Urbach tails, thus presenting a trade-off scenario. Based on these requirements, we have designed a CMOScompatible, band-gap engineered nitride platform with ultra-rich silicon content. The silicon nitride material is compositionally engineered to have a band-gap energy of 2.1 eV, which is low enough to confer a high Kerr nonlinearity, but still well above the energy required for the TPA process to occur. The new material, which we called ultra-silicon-rich nitride (USRN), has a material composition of Si7N3, a high Kerr nonlinearity of 2.8x10-13 cm2/W, and a negligible TPA coefficient. In optical amplification experiments, 500 fs pulses at 14 W peak power and centered around 1560 nm are combined with continuous wave signals. The maximum parametric gain of the signal could reach 42.5 dB, which is one of the largest gains demonstrated on CMOS platforms to date. Moreover, cascaded four-wave mixing down to the third idler, which was usually observed for mid-infrared silicon waveguides, is unprecedentedly observed at this spectrum.

Continuous wave four-wave mixing (FWM) in ultra-silicon-rich nitride photonic crystal waveguides (PhCWs) is demonstrated using low coupled pump powers. A conversion efficiency of −37 dB was observed using a 776 um long PhCW.

Nonlinear optics leveraging CMOS-compatible, ultra-silicon-rich nitride devices is presented. Films are engineered to possess high Kerr nonlinearity and negligible two-photon absorption at telecommunications wavelengths. We demonstrate high-gain optical parametric amplifiers, wavelength conversion, supercontinuum sources and slow light enhanced devices.

We characterize the nonlinear optical properties of GeSbS chalcogenide glasses with fiber-based experiments. A waveguide nonlinear parameter of 7 W−1/m and nonlinear refractive index of 3.71 × 10−18 m2/W are estimated by self-phase modulation. A GeSbS waveguide could also generate a supercontinuum from 1280 to 2120 nm at the −30 dB level for maximum coupled power of 340 W, showing a 14 fold spectral broadening of the input spectrum explained by cascaded stimulated Raman scattering.

We study ultrafast spectral characteristics of our ultra-short ultra-slicon rich nitride (USRN) waveguide with large Kerr nonlinearity (γ∼550W−1/m) and negligible nonlinear loss. The output spectra of USRN ring resonator and short-length waveguide broaden around 2 times and 4 times wider than that in 500 fs input pulses, respectively. Negligible nonlinear loss including two-photon absorption at near-infrared wavelength rages is proven by the linear increase in both the output bandwidth and power versus input peak power up to 100 W. The bandwidth broadens by 200 nm per millimeter of USRN waveguide implying that our ultra-short USRN waveguide acquires higher spectra-broaden efficiency compared other CMOS-platforms operating at telecommunication bands.

GeSbS ridge waveguides have recently been demonstrated as a promising mid – infrared platform for integrated waveguide – based chemical sensing and photodetection. To date, their nonlinear optical properties remain relatively unexplored. In this paper, we characterize the nonlinear optical properties of GeSbS glasses, and show negligible nonlinear losses at 1.55 μm. Using self – phase modulation experiments, we characterize a waveguide nonlinear parameter of 7 W[subscript −1]/m and nonlinear refractive index of 3.71 × 10[superscript −18] m[superscript 2]/W. GeSbS waveguides are used to generate supercontinuum from 1280 nm to 2120 nm at the −30 dB level. The spectrum expands along the red shifted side of the spectrum faster than on the blue shifted side, facilitated by cascaded stimulated Raman scattering arising from the large Raman gain of chalcogenides. Fourier transform infrared spectroscopic measurements show that these glasses are optically transparent up to 25 μm, making them useful for short – wave to long – wave infrared applications in both linear and nonlinear optics., SUTD-MIT International Design Centre (IDC)