RESUMEN
We report the optical performance of a photonic receiver for laser communication applications. The receiver is composed of 14 × 12 grating coupler arrays. The received optical signal power will be combined electrically via germanium photodiodes. The photonic receiver is designed for 20-µm to 30-µm mode field diameter (MFD) input sources. To maximize the fill factor of the 200 µm × 200 µm light-receiving area, a design strategy has been proposed. (1) Grating couplers are customized for compactness. (2) Periods of grating couplers are designed to work as end-fire and back-fire grating couplers for the same incident angle of the input laser source. (3) Different widths of waveguides are routed to minimize cross talk. The photonic receiver is evaluated with a 10-µm MFD source. As a result of the evaluation, the receiving area considering the minimum efficiency of -10.5â dB is 95% of the designed area when illuminating 20-µm to 300-µm MFD laser sources.
RESUMEN
Compact wavelength splitters based on angled multimode interferometers (AMMIs) on silicon nitride platforms working in visible lights are reported for fluorescence sensing applications. A diplexer and triplexer with different footprints are designed and experimentally demonstrated. The diplexer and triplexer have the insertion loss of â¼1.7 and â¼2.7 dB/channel with cross talks of less than -22 dB and -17 dB on target wavelengths, respectively. These splitters are used to distinguish the signals collected from two fluorescent dyes that give different emission spectra when excited with an excitation source, due to their different Stokes shifts. In the case of the triplexer, a third port is to collect the excitation light, both to monitor the remaining excitation power and to reduce the interference at the signal ports. A termination structure at the end of the AMMIs and input and output tapering waveguides as a part of the wavelength splitters are designed and their performances are presented.
