Superluminescent light-emitting diode with reverse biased absorber
US5252839A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 10, 1992 |
| Grant date | Oct 12, 1993 |
| Priority date | — |
| Expiry date | Jun 10, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/3434
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A non-lasing edge-emitting LED (30) suitable for precision reflectometry has an absorber region (52) which is reverse-biased via a contact (58) to absorb light by Stark absorption or Franz-Keldysch effect. During operation, the gain region (50) is forward biased via contact (56) to produce light emission including stimulated emission from an edge of the device, The absorber region is sized to a length L.sub..alpha. >(gL.sub.g -1/21n(1/R.sub.1 R.sub.2))/.alpha. where g and .alpha. are coefficients of gain and absorption and R.sub.1 and R.sub.2 are the front and back facet (60, 64) reflectivities, such that round-trip power loss through the cavity is at least 60 dB. The length L.sub..alpha. is sufficient to preclude regenerative oscillation of light in the cavity during light emission including stimulated emission. Antireflection measures further reduce end facet reflectivity, limiting signal contributions due to internal reflections to less that -85 dB below the primary output signal. Controlling cavity width reduces sidewall reflections and using step-biased segmented contacts reduces gain/absorber interface reflections.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.