Vector modulation of split-contact DFB lasers
Abstract
Multisection DFB lasers are currently of interest both for coherent FSK systems, which require a wide electrical tuning range and a large flat FM response, and for high-bit-rate direct detection systems which require wide-bandwidth, low-chirp AM response. This paper reports a method of assessing and displaying the FM and AM response of two- and three-section lasers when the modulating signal is applied in different proportions to all the sections. With such vector modulation, an improvement in the magnitude of the FM response could be obtained, together with a decrease in the residual AM. As expected, the FM response of these devices under vector modulation did not reflect their static tuning contours.
- Publication:
-
IEE Proceedings J: Optoelectronics
- Pub Date:
- April 1991
- Bibcode:
- 1991IPOpt.138..109H
- Keywords:
-
- Amplitude Modulation;
- Distributed Feedback Lasers;
- Frequency Modulation;
- Frequency Shift Keying;
- Chirp;
- Optical Heterodyning;
- Tuning;
- Lasers and Masers