Study of III-V Waveguide Photodetectors for Photonic Integrated Circuits

The spectral and threshold characteristics of a 30 μm microdisk laser coupled to an optical waveguide made from the same heterostructure were studied. Both the microlaser and the waveguide had an active region based on the 5 layers of InGaAs/GaAs quantum dots. The measurements were carried out in continuous wave regime at the room temperature. The microlaser had the threshold current of 25 mA. The laser generation was mostly single-mode. The spectral position of the lasing mode at the injection current near the threshold was 1056 nm. At the injection current of 28 mA the laser generation shifted on the other nearest whispering gallery mode at a wavelength of 1059.7 nm. The dependence of the dark current of the 217 μm waveguide photodetector with an active region based on InGaAs/GaAs quantum dots on the reverse bias was studied. The dark current had a value of less than 1.5 nA with a reverse bias value up to -20 V. The optocoupler based on the studied microdisk laser coupled to the optical waveguide as a radiation source and the studied waveguide photodetector was implemented.