External Cavity Coherent Transmitter Modules
Abstract
This report covers work done with a Fabry-Perot semiconductor laser based external cavity structure, for use with coherent fiber optical communications systems. A novel structure was developed which uses a single-mode fiber as part of the external cavity, together with a graded-index rod lens and a diffraction grating end reflector. The advantages of choosing this structure are highlighted, the principal being that it can be used with any modulation format, at any bit rate and also as the transmitter laser or the local oscillator laser. The latter has to have wide tunability so that the coherent receiver can select closely packed optical channels, and the structure selected is the only one that offers very wide turnability of over 100nm or 12,000 GHz. Various measurements done with this structure are included in this report. Extensive theoretical work an spectral linewidth and tunability is also reported and detailed comparison of the above structure is made with those based on distributed feedback lasers and also having external cavities. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1990
- Accession Number
- ADA230239
Entities
People
- Harish Sunak
Organizations
- University of Rhode Island