Slow chirp compensation for enhanced signal bandwidth and transmission performances in directly modulated lasers
US8027593B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 8, 2008 |
| Grant date | Sep 27, 2011 |
| Priority date | — |
| Expiry date | May 28, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/58
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The frequency chirp modulation response of a directly modulated laser is described using a small signal model that depends on slow chirp amplitude s and slow chirp time constant τs. The small signal model can be used to derive an inverse response for designing slow chirp compensation means. Slow chirp compensation means include electrical compensation, optical compensation, or both. Slow chirp electrical compensation can be implemented with an LR filter or other RF circuit coupled to a direct modulation source (e.g., a laser driver) and the directly modulated laser. Slow chirp optical compensation can be implemented with an optical spectrum reshaper having a rounded top and relatively large slope (e.g., 1.5-3 dB/GHz). The inverse response can be designed to under-compensate, to produce a flat response, or to over-compensate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.