Yong-Ping Liao

Etching mask optimization of InAs/GaSb superlattice mid-wavelength infared 640 × 512 focal plane array

In this paper we focused on the mask technology of inductively coupled plasma (ICP) etching for the mesa fabrication of infrared focal plane arrays (FPA). By using the SiO2 mask, the mesa has higher graphics transfer accuracy and creates less micro-ripples in sidewalls. Comparing the IV characterization of detectors by using two different masks, the detector using the SiO2 hard mask has the of , while the detector using the photoresist mask has the of in 77 K. After that we focused on the method of removing the remaining SiO2 after mesa etching. The dry ICP etching and chemical buffer oxide etcher (BOE) based on HF and NH4F are used in this part. Detectors using BOE only have closer to that using the combining method, but it leads to gaps on mesas because of the corrosion on AlSb layer by BOE. We finally choose the combining method and fabricated the 640× 512 FPA. The FPA with cutoff wavelength of 4.8 m has the average of and the average detectivity of at 77 K. The FPA has good uniformity with the bad dots rate of 1.21% and the noise equivalent temperature difference (NEDT) of 22.9 mK operating at 77 K.

Room-Temperature Operation of 2.4 μm InGaAsSb/AlGaAsSb Quantum-Well Laser Diodes with Low-Threshold Current Density

GaSb-based 2.4 μm InGaAsSb/AlGaAsSb type-I quantum-well laser diode is fabricated. The laser is designed consisting of three In0.35Ga0.65As0.1Sb0.9/Al0.35Ga0.65As0.02Sb0.98 quantum wells with 1% compressive strain located in the central part of an undoped Al0.35Ga0.65As0.02Sb0.98 waveguide layer. The output power of the laser with a 50-μm-wide 1-mm-long cavity is 28mW, and the threshold current density is 400 A/cm2 under continuous wave operation mode at room temperature.

2-μm single longitudinal mode GaSb-based laterally coupled distributed feedback laser with regrowth-free shallow-etched gratings by interference lithography*

We report a type-I GaSb-based laterally coupled distributed-feedback (LC-DFB) laser with shallow-etched gratings operating a continuous wave at room temperature without re-growth process. Second-order Bragg gratings are fabricated alongside the ridge waveguide by interference lithography. Index-coupled LC-DFB laser with a cavity of 1500 μm achieves single longitudinal mode continuous-wave operation at 20 °C with side mode suppression ratio (SMSR) as high as 24 dB. The maximum single mode continuous-wave output power is about 10 mW at room temperature (uncoated facet). A low threshold current density of 230 A/cm2 is achieved with differential quantum efficiency estimated to be 93 mW/A. The laser shows a good wavelength stability against drive current and working temperature.

Temperature- and current-dependent spontaneous emission study on 2 µm InGaSb/AlGaAsSb quantum well lasers

Spontaneous emission measurements, as a function of injection current and temperature, were carried out from the sidewall of a working 2 ?m InGaSb/AlGaAsSb quantum well laser. The local Z power parameter was extracted to investigate the carrier recombination behaviors. A model involving the activation energy is presented to interpret the carrier loss mechanisms. Our findings show that the majority of the injected carriers recombine radiatively at low injection currents, and that Auger nonradiative recombination increases significantly with injection current. More importantly, no obvious temperature dependence of Z is observed from 20 to 80 ?C.

Tuning exciton energy and fine-structure splitting in single InAs quantum dots by applying uniaxial stress

Exciton and biexciton emission energies as well as excitonic fine-structure splitting (FSS) in single InAs/GaAs quantum dots (QDs) have been continuously tuned in situ in an optical cryostat using a developed uniaxial stress device. With increasing tensile stress, the red shift of excitonic emission is up to 5 nm; FSS decreases firstly and then increases monotonically, reaching a minimum value of approximately 10 μeV; biexciton binding energy decreases from 460 to 106 μeV. This technique provides a simple and convenient means to tune QD structural symmetry, exciton energy and biexciton binding energy and can be used for generating entangled and indistinguishable photons.

MBE growth and fabrication of 2.Xμm InGa(As)Sb/AlGaAsSb laser

2.X μm InGa(As)Sb/AlGaAsSb compressively strained quantum wells laser has been grown and fabricated. Antimonide laser with 1.5mm*90μm without AR/HR emitted 550mW of continuous wave output power at 2μm.And 2.4μm laser without AR/HR output 195mW at room temperature.