Wavelength Division Multiplexing has become the leading technology for optical transmission systems which operate at 1550 nm. One of the key components of such systems are tunable and wavelength selective receivers. In this paper we present a fibre-coupled two-chip receiver front end, which is highly wavelength selective and tunable over a wide wavelength range. The device is a bulk-micromachined Fabry-Perot pin-photodiode, which features a high finesse of more than 220 with a sufficient tuning range (> 40 nm) to cover wide wavelength region. The bandwidth (full-width half maximum) of the device is < 0.2 nm (25 GHz). The photocurrent crosstalk from an adjacent channel (100 GHz spaced apart) is below -30 dB. The wavelength tuning is achieved by a change in the resonator length, formed by the two chips. This is realized by current induced thermal heating on top of the membrane mirror suspensions, which deflects the membrane. The optical-electrical conversion takes place in the pin-photodiode. This integration reduces the need for any additional components. Fiber-coupling is achieved with a fiber-coupled lens that tailors the Gaussian beam to match with the Fabry-Perot cavity. The alignment process of the two-chip structure, forming the wavelength selective cavity, has been simplified to the point where a simple place-and-fix strategy can be applied.

Date Published: 25 March 2004
PDF: 9 pages
Proc. SPIE 5277, Photonics: Design, Technology, and Packaging, (25 March 2004); doi: 10.1117/12.522044

Published in SPIE Proceedings Vol. 5277:
Photonics: Design, Technology, and Packaging
Chennupati Jagadish; Kent D. Choquette; Benjamin J. Eggleton; Brett D. Nener; Keith A. Nugent, Editor(s)