A tunable V-cavity laser based on half-wave multimode interference reflector (MIR-VCL) which operates in O-band is purposed and experimentally demonstrated. The superior side mode suppression ratio (SMSR) is achieved by the halfwave MIR, which is analyzed through the theory of multimode interference coupler. The laser is fabricated on the five quantum wells (QWs) InGaAlAs/InP wafer whose PL peak is about 1300 nm and has a compact device size of 500 µm × 350 µm. With the injection current on the gain electrode and short cavity electrode fixed, 27 channels with a spacing of about 100 GHz are obtained by tuning the injection current on the long cavity electrode. Experimental results show that among the whole tuning range, the SMSR ranges from 35 dB to 41.5 dB. By controlling the injection current on gain electrode and the TEC temperature, 51-channel wavelength tuning from 1288 nm to 1318 nm is obtained. The laser reaches its threshold when the total injection current is 65 mA. The tunable MIR-VCL in O-band has good potential for applications in 5G front-haul and datacenter networks.
The monolithic integration of a tunable V-coupled-cavity laser based on half-wave multimode interference reflector (MIR-VCL) with a travelling-wave Mach-Zehnder modulator (TW-MZM) on generic InP foundry platform is present in this paper. The formation mechanism of pi-coupling-phase difference and the contradiction among loss, optimal coupling phase difference and optimal coupling coefficients of half-wave coupler are analyzed. Single electrode tuning of 11 channels of about 7.3nm wavelength range is obtained, which is determined by the cavity length and the 10% cavity length difference. Among the whole wavelength tuning range, the side mode suppression ratios (SMSRs) are all above 35dB and the typical one is about 42dB. The Mach-Zehnder modulator with optimized travelling wave electrode is integrated with the MIR-VCL by two two-ports MIRs, which could provide optical feedback for laser and CW light for MZM in the meantime. The monolithic integrated transmitter on generic InP platform is free of complicated fabrication process of grating structure and has good potential for cost effective applications.
Currently various types of aircraft booming and maturing, however, their long-time navigational capability should be improved urgently. This paper aims at studying laser power beaming, which includes the technology of high-efficient photoelectric conversion and APT(acquiring, pointing and tracking) technology, to provide power for flying UAV(unmanned aerial vehicles) and improve their flight endurance.
The experiment of testing different types of solar cells under various conditions has been done to choose the solar cell which has the highest photoelectric conversion rate and find its most sensitive wavelength. In addition, the charge management module has been chose on the base of the characteristics of lithium batteries. Besides, a laser APT system was designed and set up, at the same time FSM (Fast Scan Mirror) control program and digital image processing program were used to control the system. The success of the indoor experiment of scan-tracking and charging for the moving UAV model via laser proves that this system is workable. And in this experiment, the photoelectric conversion rate of the whole system is up to 17.55%.