Lei LIN^*, Yujie LIU, Chulchae CHOI, Xueping ZHANG and Ray T. CHEN

Microelectronics Research Center, Department of Electrical and Computer Engineering, University of Texas at Austin, Austin, TX 78758, U.S.A.

(Received July 17, 2001; Accepted September 19, 2002)

We report here a demonstration of hybrid integration of a 1×12 metal–semiconductor–metal (MSM) photodetector array and polyimide channel waveguides via 45^° total-internal-reflection (TIR) micro-couplers. The two-layer polyimide waveguide array was constructed using Ultradel 9120D for the core and Ultradel 9020 for the lower cladding layer. The coupling loss and propagation loss of the waveguide are 0.2 dB and 0.21 dB/cm, respectively. The cross talk of the adjacent channels is -32 dB. The MSM photodetector array was fabricated on a semi-insulated GaAs wafer. The photodetectors are integrated to operate in the conventional vertical illumination mode. We measured the external quantum-efficiency and 3 dB bandwidth of the integrated MSM photodetectors at 0.4 A/W and 2.648 GHz, respectively. The aggregate 3 dB bandwidth of the 12-channel integrated system is 32 GHz.

Key words: MSM photodetector, optical interconnect, polymer waveguide, integrated system, mirror coupler

^*Correspondance: University of Texas at Austin, PRC/MER Bldg 160 Room 1.108, 10100 Burnet Road, Austin, TX, 78758, U.S.A.
E-mail address: llin2@ece.utexas.edu