Acousto-optic filter with near-ideal bandpass characteristics
US5400171A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 1, 1993 |
| Grant date | Mar 21, 1995 |
| Priority date | — |
| Expiry date | Oct 1, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F2203/055
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An acousto-optic tunable filter (100) is provided with an acousto-optic interaction profile that results in a frequency response with near-ideal bandpass filter characteristics of near-unity transmission inside the passband and near-zero transmission outside the passband. The acousto-optic interaction profile which results in this frequency response has a phase polarity which alternates and is damped, i.e. the acousto-optic interaction profile has a damped oscillating shape. The physical structure to implement this filter comprises a pair of acoustical waveguides (110, 112) which taper toward each other at the beginning of the profile and then are spaced apart by a constant distance. A damping layer (132) or other damping structure is provided to achieve the damping characteristics of the profile.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.