<title>High-speed monolithic integrated technologies for wavelength division multiplexing and demultiplexing based on VCSELs</title>

Abstract

Monolithic multiple-wavelength arrays of vertical-cavity surface-emitting lasers (VCSEL) and resonance-enhanced photodetectors (REPD) with matching wavelengths are useful for wavelength-division multiplexed optical interconnects, in which parallelism is achieved using a single fiber. Multiple wavelength channels can be optically multiplexed and broadcast to different nodes, where they are demultiplexed (selected) by REPDs with different spectral selectivity. Alternatively, the multiplexed data can be spectrally separated and sent to different destinations. Wavelength-graded VCSEL arrays with a 57 nm wavelength span have been realized, and VCSELs have been integrated with REPD arrays for improved wavelength matching. Wavelength multiplexing and demultiplexing are demonstrated at > 1 Gb/s using quasi-planar, multi-wavelength, InGaAs (VCSEL) and REPD arrays with closely matching wavelengths, with a crosstalk of > 10 dB between channels approximately 4 nm apart. The transmission performance of a single-channel fiberoptic link with a 1 km span is characterized, and the impact of optical crosstalk from neighboring wavelength channels and the effect of thermally-induced wavelength de- tuning are studied.