학술논문

Resonant Cavity 4-λ Integrated 4×4 PD-Array for High Optical Alignment Robustness WDM-FSO Communications
Document Type
Periodical
Source
Journal of Lightwave Technology J. Lightwave Technol. Lightwave Technology, Journal of. 41(8):2465-2473 Apr, 2023
Subject
Communication, Networking and Broadcast Technologies
Photonics and Electrooptics
Wavelength division multiplexing
Optical fibers
Photodetectors
Optical reflection
Optical receivers
Optical device fabrication
Optical crosstalk
Free space optical communication
high speed
resonant cavity photodetector
two-dimensional photodetector array
wavelength division multiplexing
Language
ISSN
0733-8724
1558-2213
Abstract
We present a newly developed resonant cavity 4-λ integrated two-dimensional 4 × 4 photodetector array (2D-PDA) device and its application for a wavelength-division-multiplexing (WDM) free-space optical (FSO) communication. The 2D-PDA enables direct optical coupling to the FSO beam, simplifying the optical alignment process needed for 10 μm single-mode fiber coupling and reducing the need for beam-tracking function. In the WDM-FSO communication demonstration, a four-wavelength beam in free space was successfully received by 4-different cavity length PD pixels in 4 × 4 PDA with crosstalk between each channel. This paper discusses about the fabrication and characteristic of the 2D-PDA device, in addition to the 25 Gbps/λ FSO communication demonstration using the 4 × 4 2D-PDA. Considering the crosstalk, the bit error rate is discussed in the 2-WDM and 3-WDM FSO communication demonstrations at 25 Gbps/λ.