Hybrid rugate filter assembly for temperature stabilized emission of grating coupled surface emitting lasers
US5111467A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 10, 1990 |
| Grant date | May 5, 1992 |
| Priority date | — |
| Expiry date | Sep 10, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/141
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A dielectric film is deposited on a glass substrate which is transparent to the emission wavelength of a grating coupled surface emitting laser. The dielectric film has a continuously varying refractive index with thickness, usually in the form of a sine wave. The rugate filter is assembled to overlie the second order grating of the laser so that a peak wavelength .lambda..sub.p is reflected back into the second order grating which couples the light into the laser. By reflecting light at the peak wavelength back into the laser, the laser is caused to emit at the desired wavelength. Since the rugate filter selectively reflects light within a narrow band of the desired wavelength, the laser emits light within the same narrow band which can be set to any wavelength by choosing the rugate filter's grating period. The use of a rugate filter separately assembled from the laser permits the creation of a matrix of filters, each filter fabricated to select a discrete wavelength so that a single array of surface emitting lasers can emit at multiple distinct stabilized wavelengths according to the filters in the matrix.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.