Abstract

Wavelength-division multiplexed (WDM) systems are under investigation for applications ranging from high capacity inter-exchange links, through local area networks, to processor interconnects in computers.¹ Compact hybrid demultiplexers have been reported.² However, integration offers advantages in terms of size, field-worthyness, and cost. Integration in InP-based material additionally allows the possibility of combining a passive muitiplexer/demultiplexer monolithically with a laser source or a photodector for the fabrication of a multi-wavelength transmitter and receiver. Recently, there have been a couple of reports of wavelength demultiplexers implemented in InP waveguide material,^3,4 on demonstrating 20 channel demultiplexing at a 4nm channel spacing.⁴ In this paper, we present a monolithic single grating demultiplexer which resolves 78 channels separated by 1 nm, centered on 1.51 pm in the low loss fiber band. In contrast to previous devices, this demultiplexer is essentially insensitive to the polarization of the incident light.

© 1991 Optical Society of America