Semiconductor laser noise reduction
US5199038A · kind A · utility
Inventors
Key dates
| Filing date | May 14, 1991 |
| Grant date | Mar 30, 1993 |
| Priority date | — |
| Expiry date | May 14, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S2301/02
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Amplitude or intensity noise in the output of a laser in detuned operation is reduced by application of a frequency dependent transfer function which exploits amplitude-phase coupled noise described by the linewidth enhancement parameter .alpha. by applying an inverse of a replica of the amplitude noise recovered from the phase noise to the laser output. The noise canceling amplitude is applied to the laser output by a filter whose frequency dependent transfer function is related to the inverse of the amplitude-phase noise transfer function of the laser producing the output. The appropriate transfer function may be selected and/or adjusted in response to the magnitude of the amplitude noise. The intensity noise may be reduced by the factor 1/(1+.alpha..sup.2) which may squeeze the intensity noise below normal quantum limits.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.