Wavelength-Tunable Microring Resonator on Lithium Niobate

A wavelength-tunable microring resonator with integrated microheater on lithium niobate is presented. Ridge structure on lithium niobate is formed by a wet-etching technique for enhancing the lateral index contrast of the waveguide. The resonant wavelength of the microring resonator is tuned through thermooptic effect by injecting current into the integrated microheater. The tuning characteristics of through port and drop port are measured and the tuning rates in the microring resonator with a radius of 100 mum for transverse-magnetic and transverse-electric polarizations are 2.54 x 10^-2 nm/mA and 3.40 x 10^-3 nm/mA.     

High-power high-Modulation-speed 1060-nm DBR lasers for Green-light emission

We report on the static and dynamic performance of high-power and high-modulation-speed 1060-nm distributed Bragg reflector (DBR) lasers for green-light emission by second-harmonic generation. Single-wavelength power of 387 mW at 1060-nm wavelength and green power as high as 99.5 mW were achieved. A thermally induced wavelength tuning of 2.4 nm and a carrier-induced wavelength tuning of -0.85 nm were obtained by injecting current into the DBR section. Measured rise-fall times of 0.2 ns for direct intensity modulation and 0.6 ns for wavelength modulation make the lasers suitable for >50-MHz green-light modulation applications.     

Ultrasmall Thermally Tunable Microring Resonator With a Submicrometer Heater on Si Nanowires

An ultracompact widely tunable thermooptical (TO) microring resonator (MRR) filter based on Si nanowires is presented. The Si nanowire waveguide has a insulator, Si core, a up-cladding, and a thin metal film at the top. The metal circuit along the microring is used as a submicrometer heater which has the same width as the Si nanowire waveguide. The up-cladding is optimized to reduce the light absorption of the metal as well as to have a good heat-conduction from the heater to the Si core. Two pads used as the contact points for the probes connecting to the electrical power are perpendicularly connected to the microring by using optimized T-junctions (with a low excess loss of about 0.06 dB per T-junction). With such a design, the present thermally tunable microring resonator (MRR) can be fabricated by using a standard fabrication process with a single lithography process, which is much simpler than the fabrication with double lithography processes used for the conventional TO components. Finally, the simulation results show that the designed MRR has a wide tuning range of about 20 nm with a low heating power of 5 mW.     

基于氮化硅微环和载波分离的可重构微波光子带通滤波器

基于Add-Drop型氮化硅微环滤波器,利用光学单边带调制和光载波分离的方法,实现可重构微波光子带通滤波器。滤波器带宽和带外抑制比分别达到726 MHz和37.0dB。并且通过改变光载波波长实现1.64~23.41GHz的滤波器频率调谐;通过调节微环耦合系数实现0.683~2.246GHz的滤波器带宽调谐,在带宽调谐范围内带外抑制比大于26dB。     

光纤光栅调谐全光纤激光器

本文提出了一种利用光纤光栅作为调谐装置的可调谐全光纤激光器。实验结果表明：该调谐装置操作简便,性能稳定。激光器输出波长连续可调,输出波长复现性误差小于０．００８ｎｍ,输出功率大于１ｍＷ,激光谱线宽小于０．０１ｎｍ,波长调谐范围大于６．４ｎｍ。     

基于微环谐振器的超紧凑微波光子滤波器的设计

设计了一个基于硅基微环的超紧凑的微波光子滤波器,用以提高硅基微波光子器件的集成密度及增大其自由光谱范围。根据波导光学的耦合模理论,推导出双环并联谐振器的光强传递函数,并通过仿真得到了微波光子滤波器的输出特性。结果表明:当微环半径为0.79 m时,谐振器中直波导宽度为0.3 m,环形波导宽度为0.25 m,滤波器的自由光谱范围为140 nm,插入损耗为0.5 dB,半峰全宽为7 nm,此滤波器的性能完全满足粗波分复用系统的要求。     

A Novel Two-Section Tunable Discrete Mode Fabry-PÉrot Laser Exhibiting Nanosecond Wavelength Switching

A novel widely tunable laser diode is proposed and demonstrated. Mode selection occurs by etching perturbing slots into the laser ridge. A two-section device is realized with different slot patterns in each section allowing Vernier tuning. The laser operates at 1.3 mum and achieves a maximum output power of 10 mW. A discontinuous tuning range of 30 nm was achieved with a side mode suppression greater than 30 dB. Wavelength switching times of approximately 1.5 ns between a number of wavelength channels separated by 7 nm have been demonstrated.     

Sampled grating tunable twin-guide laser diodes with over 40-nm electronic tuning range

Device and tuning characteristics of sampled grating tunable twin-guide laser diodes are presented. The vertically integrated, monolithic widely tunable laser requires only two tuning currents to fully cover a wavelength range of more than 40 nm by electrooptic tuning. Its tuning behavior is quasi-continuous with up to 8.2-nm broad continuous tuning regions. High sidemode suppression (SMSR /spl ges/ 35 dB) as well as large output power (P /spl ges/ 10 mW) are obtained over the wavelength range from 1520.5 to 1561.5 nm.     

可调谐氮化硅波导微环谐振腔滤波器研究

设计并制备了一种基于热光效应的集成可调谐氮化 硅(Si₃N₄)波导微环谐振腔滤波器,通过采用马赫-曾德干涉仪(MZI)构成的可调谐 耦合器控制耦合区耦合比,以实现滤波器消光比的调谐。设计并优化了微环谐振 腔的波导截面尺寸、弯曲半径和耦合区波导间隔等参数,并通过光刻、反应离子刻蚀(RIE )等工艺制备 了两种不同弯曲半径的Si₃N₄波导微环谐振腔。实验结果表明,本文器件在波长1550nm附近处的自由光谱 范围(FSR)为68pm,3dB带宽约为16pm,品质因子Q达到了9.68×10 4,消光比可调范围约为17dB。     

High-performance all-optical silicon microswitch

An integrated micron-size all-optical Si switch capable of 94.7 GHz operation frequency is presented. The device consists of a microring resonator formed by Si/SiO/sub 2/ slot-waveguides with a low-index nonlinear optical material in the slot region. Strong optical confinement in the slot permits an achievement of low switching power of 6.2 mW.     

Electrooptic narrow linewidth wavelength tuning and intensity modulation of an erbium fiber ring laser

We report an electrically tunable fiber laser featuring a 50-channel wavelength switching capability with a 0.2 nm linewidth and -20 dB crosstalk. The laser consists of an Er-doped fiber resonator and an electro-optic TE-TM convertor used as a wavelength tunable filter. It allows wavelength tuning over a spectral range of 10 nm with a tuning rate of 0.05 nm/V and a linewidth of 0.06 nm.     

Wavelength trimming of a microring resonator filter by means of aUV sensitive polymer overlay

Trimming of the resonant wavelength of a vertically coupled glass microring resonator channel dropping filter with a photo-induced refractive index change in a dip coated polymer overlay is reported. In this letter, the glass microring resonator has a radius of 19 μm, a free-spectral range of 10 nm, and a Q value of 800. The maximum wavelength shift observed is 9 nm, which is yielded through an absolute bulk index change in the polymer of 0.044. Trimming is a continuous function of exposure time and dose     

Tunable Optical Notch Filter Realized by Shifting the Photonic Bandgap in a Silicon Photonic Crystal Line-Defect Waveguide

A tunable optical notch filter was realized by thermally shifting the TM-like (the light's electric field perpendicular to the substrate) bandgap of a silicon photonic crystal slab W1 line-defect waveguide with silica cladding. This device is compact-its footprint is 340times16 mum², excluding the electrode pads. The 3-dB bandwidth of the device was about 5 nm, and the extinction ratio at the center wavelength was as high as 40 dB. A maximum center wavelength shift of 17.9 nm was attained at a heating power of 0.7W, with a tuning efficiency of 25.5 nm/W. The tuning response time was less than 100 mus     

Polymer microring coupled-resonator optical waveguides

We present measurements of the transmission and dispersion properties of coupled-resonator optical waveguides (CROWs) consisting of weakly coupled polymer microring resonators. The fabrication and the measurement methods of the CROWs are discussed as well. The experimental results agree well with the theoretical loss, waveguide dispersion, group delay, group velocity, and group-velocity dispersion (GVD). The intrinsic quality factors of the microrings were about 1.5/spl times/10/sup 4/ to 1.8/spl times/10/sup 4/, and group delays greater than 100 ps were measured with a GVD between -70 and 100 ps/(nm/spl middot/resonator). With clear and simple spectral responses and without a need for the tuning of the resonators, the polymer microring CROWs demonstrate the practicability of using a large number of microresonators to control the propagation of optical waves.     

Electrooptic tuning of a fiber ring semiconductor laser

This letter reports recent results obtained in the area of wavelength tuning of semiconductor lasers. The laser is constructed from an InGaAsP 1300-nm semiconductor optical travelling-wave amplifier. The cavity consists of a fiber ring resonator using a low fiber coupler as the output mirror. The intra-cavity electrooptic tuner works as a one-stage Lyot filter and allows wavelength tuning over a spectral range of 20 nm with a tuning rate of 0.05 nm V^-1. This is one of the best results reported using electrooptic birefringent tuning systems     

Tunable Optical Add–Drop Multiplexer Based on Silicon Photonic Wire Waveguides

A wavelength tunable optical add–drop multiplexer based on silicon photonic wire waveguides with Bragg-grating-reflectors was demonstrated by tuning the dropping wavelength through thermooptic effect. A 6.6-nm dropping wavelength shift was obtained at a 0.82-W heating power. For the device that is presently polarization-dependent, the 3-dB channel-dropping bandwidth was 0.4 nm and the extinction ratio at the dropping wavelength for port THROUGH was better than 17 dB for assuming 1.6-nm wavelength spacing dense wavelength-division multiplexing. The average tuning speed was about 200$muhboxs$.     

Ring-Based Triple-Push VCOs With Wide Continuous Tuning Ranges

This paper proposes a new ring-based triple-push voltage-controlled oscillator (VCO) architecture to achieve a wide tuning range and high operating frequencies. Two ring-based triple-push VCOs, one with a continuous frequency tuning range of 0.2-34 GHz, fabricated in 0.13- mum CMOS, and the other with a range of 0.1-65.8 GHz, fabricated in 90-nm CMOS, are presented in this paper. These two VCOs demonstrate that the proposed VCO architecture can achieve a very wide continuous tuning range, up to millimeter-wave frequencies, without any device-switching operations. In addition to the wide tuning range, the chip area of the proposed VCO is very small, allowing integration into a phase-locked loop. The power consumptions of the 0.2-34- and 0.1-65.8-GHz VCOs are 2-70 mW from a 2-V supply voltage, and 1.2-26.4 mW from a 1.2-V supply voltage, respectively. The fundamental and second harmonic rejections are better than 15 dB for both VCOs.     

High-Power Single-Mode Distributed-Feedback Interband Cascade Lasers for the Midwave-Infrared

A single-mode output power of 41 mW has been obtained at T=120 K and lambdaap3.44 mum from a narrow-ridge interband cascade laser patterned with a Ge distributed-feedback grating. The sidemode suppression ratio at the maximum power is 23 dB, and the linewidth of 0.1 nm is instrument-limited. An alternate contacting geometry yielded robust single-mode output over a broad range of currents and temperatures, and current tuning of the wavelength by up to 17 nm     

InAs–InP (1.55- μm Region) Quantum-Dot Microring Lasers

In this letter, we demonstrate electrically pumped continuous-wave lasing at room temperature in microring lasers, which employ a quantum-dot gain medium. Lasing occurs in the important 1.55-mum telecom wavelength range. The 2-mum-wide ring waveguides are made from InGaAsP-InP (100) material suitable for active-passive photonic integrated circuits. Lasing in rings down to 22 mum in diameter is found, with a threshold current of 12.5 mA.     

Non-blocking wavelength channel switch using TO effect of doubles series coupled microring resonator

A non-blocking wavelength channel switch (non-blocking tunable filter) using the thermo-optic (TO) effect of a double series coupled polymer microring resonator is demonstrated. This device can switch a wavelength channel without blocking other wavelength channels. An extinction ratio of more than 10 dB was realised.