Semiconductor laser
US5040188A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 16, 1990 |
| Grant date | Aug 13, 1991 |
| Priority date | — |
| Expiry date | Apr 16, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/1215
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A switchable DFB (distributed feedback) laser which includes a waveguide layer having an impressed diffraction grating composed of two or more superposed subgratings having different respective grating constants. The diffraction grating is either frequency modulated (FIG. 3a) or amplitude modulated (FIG. 3b) or is a mixed form of these two types of modulation. Each subgrating can be employed to generate an emission wavelength that is a function of the grating period. By changing the temperature or changing the injection current, the effective index of refraction of the laser is changed, thus enabling the setting of an emission wavelength which is a function of the modulated diffraction grating. The switchable DFB laser according to the present invention may be employed for optical data transmission and particularly in narrowband wavelength multiplex operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.