A WDM transceiver module is demonstrated wherein a surface mounted 1.3μm laser diode and 1.55μm photodiode are passively aligned to a fiber-embedded optical circuit. The module consists of a transmitting 1.3 Mm laser diode mounted on a Sisubstrate with a V-groove for fiber attachment and a receiving photodiode surface mounted on an insulating substrate which has embedded in it a single mode fiber for input/output. A WDM filter inserted into tile embedded fiber directs the incoming 1.55pmlight to the detector.For the transmitter portion, the laser is soldered onto the substrate by precision bonder with the aid of a marker for pattern recognition, and the fiber is placed in a V-groove made by etching the Si substrate. For the receiver portion, the photodiodeis surface mounted with epoxy using the microbump bonding (MBB) technique, which is placed above the fiber embedded in a trench made in the substrate. The 20Mm thick polyimide WDM filter which reflects 1.55Mm light and transmits 1.3μm light is insertedinto a slit which transverses the fiber at an angle 30 degrees normal to the substrate surface. There are. no reflecting surfaces in the photodiode portion, because index matching epoxy is used both to hold the filter in place and in the MBB process.The characteristics of this module are as follows. The output power at 13μm was greater than 1.5mW, considering a 12% coupling efficiency to the fiber. The responsivity of the photodiode was 0.85A/W at 1.55 Mm.
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