Monolithically Lens-Integrated Photonic Device Arrays for Compact Optical Transceivers

Monolithically lens-integrated surface-emitting distributed-feedback (DFB) laser arrays and p-i-n photodiode arrays were developed. A combination of dry etching and wet chemical etching was used to fabricate a monolithic InP lens. The lens profile within +/-10 mu m from the lens center was estimated to be parabolic shape, which is ideal for the collimation of a Gaussian beam. A fabricated lens-integrated surface-emitting DFB laser exhibited a circular, narrow far-field pattern with full-width at half maximums of 3.9 x 3.5 degrees. An efficient direct coupling of the lens-integrated DFB laser to a single-mode fiber with a coupling efficiency of -3 dB was confirmed. A four-channel lens-integrated surface-emitting laser array and a lens-integrated p-i-n photodiode array were used to fabricate a very compact 100 Gbps (25 Gbps x 4 channel) optical transceiver with 14 x 9 mm(2) footprint. (C) 2013 The Japan Society of Applied Physics