A complex-coupled DFB laser with sampled grating has been designed and fabricated. The method uses the +1st order reflection of the sampled grating for laser single-mode operation. The typical threshold current of the sampled grating based DFB laser is 25 mA,and the optical output is about 10 mW at the injected current of 100 mA. The lasing wavelength of the device is 1.5385 μm,which is the +1st order wavelength of the sampled grating.
A new evanescently-coupled uni-traveling-carrier photodiode (EC-UTC PD) based on a multimode diluted waveguide (MDW) structure is fabricated, analysed and characterized. Optical and electrical characteristics of the device are investigated. The excellent characteristics are demonstrated such as a responsivity of 0.36 A/W, a bandwidth of 11.5 GHz and a small-signal 1-dB compression current greater than 18 mA at 10 GHz. The saturation current is significantly improved compared with those of similar evanescently-coupled pin photodiodes. The radio frequency (RF) bandwidth can be further improved by eliminating RF losses induced by the cables, the probe and the bias tee between the photodiode and the spectrum analyzer.
The effects of the multimode diluted waveguide on quantum efficiency and saturation behavior of the evanescently coupled uni-traveling carrier (UTC) photodiode structures are reported. Two kinds of evanescently coupled uni-traveling carrier photodiodes (EC-UTC-PD) were designed and characterized: one is a conventional EC-UTC-PD structure with a multimode diluted waveguide integrated with a UTC-PD; and the other is a compact EC-UTC-PD structure which fused the multimode diluted waveguide and the UTC-PD structure together. The effect of the absorption behavior of the photodiodes on the efficiency and saturation characteristics of the EC-UTC-PDs is analyzed using 3-D beam propagation method, and the results indicate that both the responsivity and saturation power of the compact EC-UTC-PD structures can be further improved by incorporating an optimized compact multimode diluted waveguide.
A frequency and wavelength tunable self-pulsation laser based on DBR laser devices is reported for the first time.This laser generates continuous tunable optical microwave in the range of 1.87-21.81 GHz with 3-dB linewidth about 10 MHz by tuning the injection currents on the front and back gain sections,and exhibits wavelength tuning range from 1536.28 to 1538.73 nm by tuning the injection currents on the grating section.
High output powers and wide range tuning have been achieved in a sampled grating distributed Bragg reflector laser with an integrated semiconductor optical amplifier.Tilted amplifier and anti-reflection facet coating are used to suppress reflection.We have demonstrated sampled grating DBR laser with a tuning range over 38 nm,good wavelength coverage and peak output powers of more than 9 mW for all wavelengths.
This paper reports that the complex-coupled distributed feedback laser with the sampled grating has been designed and fabricated.The +1st order reflection of the sampled grating is utilized for laser single mode operation,which is 1.5387 μm in the experiment.The typical threshold current of the device is 30 mA,and the optical output power is about 10 mW at the injection current of 100 mA.
