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We systematically investigated graphene-based slot and multi-slot waveguides. A tri-slot waveguide which significantly enhances the light-graphene interaction was experimentally demonstrated with low insertion loss. By integrating a dual-layer graphene h-BN heterostructure on the tri-slot waveguide, a high efficiency modulator is designed, which combines the advantages of high modulation efficiency (0.376 dB/μm), low insertion loss (0.01 dB/μm), large modulation bandwidth (∼0.13 THz) and low power consumption (∼0.128 pJ/bit). Our work may promote the development of future high efficient graphene-based optical devices.

An energy-efficient integrated silicon Mach-Zehnder modulator using 0.5 mm long corrugated waveguides with an extinction ratio of 30 dB is presented. Using this modulator, 15 Gb/s NRZ transmission is demonstrated with modulation efficiency (Vπ L) of 0.065 V.cm.

We present an EAM based single-mode optical link. The TX uses over-peaking to improve modulation efficiency and relax TIA's noise requirement. The RX uses a 3-stage TIA with T-coils to improve bandwidth. The link achieves $BER while consuming 4.31pJ/bit at 50Gb/s with 2dB link margin.

It is a long-standing challenge to surmount the relatively low solar regulation ability in VO2-based smart window coatings. Here, we hybridize VO2 with a NiII-I-TMP complexes and then fabricate a novel composite VO2/NIT film. The composite film shows a ultra-high solar modulation efficiency (ΔTsol = 27.3%), relatively high luminous transmittance (Tlum,l = 61.3% and Tlum,h = 36.2%) and visible color modulation ability. Our novel broadband modulation composite film exhibits superior application potential in smart window application.

We first demonstrate a hybrid silicon and lithium niobate Mach-Zehnder modulator operating at C-band and O-band simultaneously. The device shows high Electro-optic modulation efficiency and bandwidth beyond 70 GHz with ultra-wide band operation.

A comparison between a graphene suspended double-layer modulator and a subwavelength-thickness modulator is presented. The physics of both are analyzed in detail and show a confined mode in the suspended modulator but a leaky mode in the subwavelength modulator. The leaky mode shows zero light–matter interaction and zero modulation depth, which should be avoided in designing a modulator. The suspended modulator can achieve much lower insertion loss and an extraordinarily higher figure of merit (∼2480) than the subwavelength modulator. Both operate with high modulation efficiency and comparable modulation speeds. We believe these designs will pave the way to realizing high-efficiency, near-fundamental-limit graphene modulators.

We report a novel silicon modulator that exploits the different modulation efficiency between two TE modes in a multimode waveguide. On-off key modulation was successfully demonstrated with an extinction ratio of 5.5 dB at 32 Gb/s.

The electric field (EF) modulation of magnetic domain wall (DW) creep velocity $v$ in Pt/Co/Pd structure with perpendicular magnetic anisotropy (MA) has been studied. The structures with different Co thickness $t_\mathrm{Co}$ up to $\sim 1$ nm are investigated. In all samples, applying a gate voltage induces a clear change in $v$. Thicker samples provide a higher $v$ modulation efficiency, and the $v$ modulation magnitude of more than a factor of 100 times is observed in the thickest $t_\mathrm{Co}$ of 0.98 nm. The parameter characterizing the creep motion is significantly affected by the EF, resulting in the modulation of $v$. Unlike the $v$ case, the MA modulation efficiency decreases with increasing $t_\mathrm{Co}$. The present results are discussed based on the EF-induced change in the interfacial Dzyaloshinskii-Moriya interaction (iDMI), which has been recently demonstrated in the same structure, and $t_\mathrm{Co}$ dependence of the DW energy. The $t_\mathrm{Co}$ dependence of the $v$ modulation suggests that the EF effect on the iDMI is more important than the MA.

We present an effective scheme to improve the modulation capacity in graphene-based silicon modulator by employing the double slots configuration with hybrid plasmonic effects. Two modulators, i.e., metal-insulator-metal and insulator-metal-insulator configurations have been demonstrated, showing that the double slots design can significantly improve the modulation efficiency. The obtained modulation efficiency is up to 0.525 dB/μm per graphene layer, far exceeding previous studies. It can be found that the light-graphene interaction plays a pivotal role in the modulation efficiency, whereas the height of metal has profound influence on the modulation. Our results may promote various future modulation devices based on graphene.

We design and demonstrate a silicon and LN hybridly integrated Mach-Zehnder interferometer modulators. The fabricated devices show a half-wave electro-optic modulation efficiency of 2.25V.cm and data rates up to 5Gbps.

An asymmetric Mach-Zehnder electro-optic modulator is fabricated through etching in 500nm thin film of Y-cut Lithium Niobate. A half wave voltage length product of 16.8Vcm and modulation efficiency of 9.4×10−3V−1 were measured for this device which is very close to what we expect from theory.

We propose an adaptive distributed-bias driving method for silicon travelling-wave Mach-Zehnder modulators and achieved ∼25% modulation efficiency enhancement at both 10 and 25 Gb/s with pp , without optimizing horizontal PN-diodes. This method also suggests a new modulator scheme allowing efficiency improvement and design flexibilities.

We propose a high efficient graphene-on-gap modulator (GOGM) by employing the hybrid plasmonic effect, whose modulation efficiency is ∼8-folds larger than that of present graphene-on-silicon modulator (GOSM) (∼0.1 dB / μm). The proposed modulator has the advantage of short modulation length ∼3.6 μm, relatively low insertion loss ∼0.32 dB and larger modulation bandwidth ∼0.48 THz. Moreover, an efficient taper coupler has been designed to convert the quasi-transverse electric (TE) mode of conventional silicon waveguide to the hybrid plasmonic mode of GOGM, with a high coupling efficiency of 91%. This study may promote the design of high-performance on-chip electro-optical modulator.

We demonstrate 10 Gb/s modulation in a 200 μm photonic crystal silicon optical modulator, in both carrier-injection and depletion modes. In particular, this is the first demonstration of 10 Gb/s modulation in depletion mode and without pre-emphasis, in a Mach-Zehnder type modulator of this length, although moderate pre-emphasis can improve the signal quality. This is made possible by utilizing the slow-light of the photonic crystal waveguide, where the group index ng is ~ 30 and gives ~ 7 times enhancement in the modulation efficiency compared to rib-waveguide devices. We observe 10 Gb/s modulation at drive voltages as low as 1.6 V and 3.6 V peak-to-peak, in injection- and depletion-modes, respectively.

A new electrooptic single-sideband modulator using resonant electrodes and polarization-reversed structures is proposed and demonstrated for the first time as far as the authors know. By adopting a polarization-reversed structure in electrooptic modulators with long standing-wave resonant electrodes, it is possible both to compensate for the degradation of modulation efficiency due to the transit-time effect and to control the phase of optical modulation arbitrarily, which leads to a compact low-power single-sideband modulator.

By optimizing the carrier distribution along the longitudinal axis of a two-section semiconductor optical amplifier (SOA), we have improved the modulation/switching performances (modulation index and efficiency, switching contrast) with respect to those of a single-section component. The modulation efficiency has been raised by up to 137%. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 126–129, 2001.

High brightness tapered lasers emitting around 650 nm were developed. We realized 2-mm-long devices with 750-mum straight section, 1250-mum tapered section, and 4deg taper angle. The input currents into both sections were independently controlled. The laser reached 500-mW output power in continuous-wave operation in a nearly diffraction-limited beam quality. A modulation efficiency of 7.5 W/A was achieved.

A high speed Si modulator with fringe field junctions is presented. Low carrier absorption (1.3 dB/mm) and Vπ L (1.8 V-cm) are demonstrated. The measured modulation speed and depth are 11.8-GHz and 8-dB.

We demonstrated a carrier-depletion type silicon Mach-Zehnder modulator with 3dB bandwidth beyond 23GHz, as well as with modulation efficiency VπL of ~1 V.cm. 30Gb/s modulation eye diagram was observed with S/N ~9.6dB.

We report a 44 Gbit/s silicon Mach-Zehnder modulator based on interleaved PN junctions. Modulation efficiency of V π L π =1.5∼2.0 V·cm and carrier induced loss of ∼1dB/mm are obtained with a moderate doping density of 2×1017 cm−3.

A high speed silicon Mach-Zehnder modulator is proposed based on interleaved PN junctions. This doping profile enabled both high modulation efficiency of V(π)L(π) = 1.5~2.0 V·cm and low doping-induced loss of ~10 dB/cm by applying a relatively low doping concentration of 2 × 10(17) cm(-3). High speed operation up to 40 Gbit/s with 7.01 dB extinction ratio was experimentally demonstrated with a short phase shifter of only 750 μm.

Simultaneous high power (2W), high modulation speed (1Gb/s) and high modulation efficiency (14 W/A) operation of a two-electrode tapered laser is reported.

Silicon p(+)-i-n(+) diode Mach-Zehnder electrooptic modulators having an ultra-compact length of 100 to 200 mum are presented. These devices exhibit high modulation efficiency, with a V(pi)L figure of merit of 0.36 V-mm. Optical modulation at data rates up to 10 Gb/s is demonstrated with low RF power consumption of only 5 pJ/bit.

We have obtained a high power of 3 W CW, 57% maximum wall-plug efficiency, a record-high modulation efficiency of 19 W/A at 700 Mb/s, more than 1.6 W optical modulation amplitude and 19 dB extinction ratio.

We report on a 1.3μm DFB laser with, to our knowledge, record modulation efficiency of 3.7GHz/mA½, demonstrating open eyes after 25km transmission at 25Gbps, under maximum positive dispersion conditions.

We demonstrate a 10 Gb/s Mach-Zehnder silicon evanescent modulator utilizing coplanar waveguide design. The device has a modulation efficiency of 1.5 V-mm and modulation bandwidth of 8 GHz.

A silicon double metal-oxide-semiconductor (MOS) capacitor structure is proposed to form a high efficient, high speed, and compact electrooptic phase modulator. The simulation results show that the modulation efficiency, Vpi Lpi , reaches 0.16 (V.cm) and the modulation speed exceeds 15 GHz.

In this paper, we report a systematic study on modulation properties of a VCSEL under ultrahigh injection-locking condition as a function of wavelength detuning (Deltalambda=lambdamaster -lambdaslave). Experimental results are explained using a new VCSEL amplifier model incorporated into the established injection-locking laser rate equations

A high direct optical modulation amplitude of more than 1.6 W, modulation efficiencies of 20 W/A at 700 Mbit/s and 50 W/A for quasi-static modulation, and a very high optical extinction ratio of 19 dB have been demonstrated in custom-designed gain guided tapered lasers emitting at 1060 nm. The devices were fabricated with split contacts, allowing the separate injection of the ridge waveguide and tapered sections. The modulation of a large output power with low modulating current was achieved by modulating the current injected into the ridge waveguide section of the device.

A two-dimensional electro-optic sampling technique with polarity modulation for THz imaging is proposed and demonstrated. The polarity modulation greatly improves the signal linearity to the THz field. Combining this technique with software lock-in detection, it is found that the modulation efficiency is also improved compared to conventional optical chopping.

A reflection-type Mach-Zehnder LiNbO3 optical modulator with a double-stub structure that can modulate both forward and backward lightwave to achieve low-driving-voltage optical modulation for band-operation is developed. Using optical reflection the modulation efficiency is doubled. The halfwave-voltage of the fabricated modulator was 2.9 V at 7 GHz.

Acousto-optic loss modulators for applications in active mode-locking of lasers are discussed. We show that intracavity interference effects can either enhance or decrease the modulation efficiency. Optical, electrical, and acoustic measurements for the characterization of mode-locking devices are described.

We report here the observation of a fall-off before the resonance peak in the small-signal modulation response of DH laser diodes. A possible explanation is proposed, taking into account the junction capacitance. Its value is estimated from the LED optical modulation efficiency and from the network electrical reflexion coefficient. Our results are compared with those of previous papers. The measured values of the shunt capacitance allow a good understanding of the experimental modulation efficiency curves of laser diodes.

Light absorption by injected holes in n‐type InSb near liquid nitrogen temperature is used to modulate the CO2 laser. A P+ N junction device is described which achieves a good modulation efficiency up to a few megahertz with a driving power of 300 mW. Such a modulator can be controlled by applying an external dc magnetic field.

We present proof-of-concept taper-less III-V/Si hybrid MOS optical phase shifter. An ultrathin InP membrane enables low insertion loss despite no taper, with keeping high modulation efficiency owing to strong electron confinement at the MOS interface.

Losses as low as 0.4 ± 0.2 dB/cm and electro-optical modulation efficiencies as high as 5°/V/mm have been obtained in single mode waveguides employing a novel buried structure in GaInAsP/InP grown by LPMOCVD and processed by selective chemical etching. Such modulators are potentially excellent candidates for integrated optoelectronics.