A contrivance of 277 nm DUV LD with B0.313Ga0.687N/B0.40Ga0.60N QWs and AlxGa1–xN heterojunction grown on AlN substrate

In this paper,an ultraviolet C-band laser diode lasing at 277 nm composed of B0.313Ga0.687N/B0.40Ga0.60N QW/QB heterostructure on Mg and Si-doped AlxGa1-xN layers was designed,as well as a lowest reported substitutional accepter and donor concentration up to NA=5.0×10^17 cm^-3 and ND=9.0×10^16 cm^-3 for deep ultraviolet lasing was achieved.The structure was assumed to be grown over bulk AIN substrate and operate under a continuous wave at room temperature.Although there is an emphasizing of the suitability for using boron nitride wide band gap in the deep ultraviolet region,there is still a shortage of investigation about the ternary BGaN in aluminum-rich AIGaN alloys.Based on the simulation,an average local gain in quantum wells of 1946 cm^-1,the maximum emitted power of 2.4 W,the threshold current of 500 mA,a slope efficiency of 1.91 W/A as well as an average DC resistance for the V-I curve of(0.336Ω)had been observed.Along with an investigation regarding different EBL,designs were included with tapered and inverse tapered structure.Therefore,it had been found a good agreement with the published results for tapered EBL design,with an overweighting for a proposed inverse tapered EBL design.

High power red-light GalnP/AlGalnP laser diodes with nonabsorbing windows based on Zn diffusion-induced quantum well intermixing

The layer structure of GaInP/AlGaInP quantum well laser diodes （LDs） was grown on GaAs substrate using low-pressure metalorganic chemical vapor deposition （LP-MOCVD） technique. In order to improve the catastrophic optical damage （COD） level of devices, a nonabsorbing window （NAW）, which was based on Zn diffusion-induced quantum well intermixing, was fabricated near the both ends of the cavities. Zn diffusions were respectively carried out at 480, 500, 520. 540, and 580 ℃ for 20 minutes. The largest energy blue shift of 189.1 meV was observed in the window regions at 580 ℃. When the blue shift was 24.7 meV at 480 ℃, the COD power for the window LD was 86.7% higher than the conventional LD.

High power AlGaInP laser diodes with zinc-diffused window mirror structure

The technology of zinc-diffusion to improve catastrophic optical damage (COD) threshold of compressively strained GaInP/AlGaInP quantum well laser diodes has been introduced. After zinc-diffusion, about 20 μm-long region at each facet of laser diode has been formed to serve as the window of the lasing light. As a result, the COD threshold has been significantly improved due to the enlargement of bandgap by the zinc-diffusion induced quantum well intermixing, compared with that of the conventional non-window structure. 40-mW continuous wave output power with the fundamental transverse mode has been realized under room temperature for the 3.5μm-wide ridge waveguide diode. The operation current is 84 mA and the slope efficiency is 0.74 W/A at 40 mW. The lasing wavelength is 656 nm.

Manufacture tolerance analysis and control for a polymer-on-silicon Mach-Zehnder-interferometer-based electro-optic switch

To enhance the electro-optic (EO) modulation efficiency and realize the impedance-matching, a polymer-on-silicon multi-mode interference (MMI) Mach-Zehnder interferometer (MZI)-based electro-optic (EO) switch is designed and optimized. Under the central operation wavelength of 1550 nm, the driving voltages of the designed switch are 0 and ±1.375 V, respectively, with a short active region length of 5 mm, and the characteristic impedance of the electrode is about 49.6 ?. The manufacture tolerance is analyzed for instructing the device fabrication. The results show that to realize ideal switching function, high fabrication accuracy on the buffer thickness, core thickness, electrode width and MMI waveguide width is extremely required, and a small voltage drift of-0.03-0.05 V is also expected for reducing the crosstalk to less than-30 dB. The allowed 3 dB bandwidth is 60 nm, and within this spectrum range, the insertion loss and crosstalk are less than 6.71 dB and-30 dB, respectively.