Synthetic aperture ladar with chirped modelocked waveform
US7505488B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 9, 2003 |
| Grant date | Mar 17, 2009 |
| Priority date | — |
| Expiry date | Mar 11, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S3/107
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention uses an intra-cavity modulation approach to modulate a laser transmitter at bandwidths greater than a few gigahertz (GHz) in a non-ambiguous waveform by chirping the laser and simultaneously mode locking. Accordingly, the inventive system includes a source of a beam of electromagnetic energy; a mechanism for mode locking the beam; and an arrangement for chirping the beam. In the illustrative embodiment, the source is a laser. The mode locking mechanism may be an active element or a passive element. The beam is chirped with a translation mirror. The translation mirror may be driven with a piezo-electric drive coupled. In the best mode, the carrier is chirped with an electro-optical crystal disposed in the cavity of the laser. The laser is chirped to the free-spectral range limit, which is typically a few hundred megahertz, by scanning the optical length of the laser resonator. After simultaneously mode locking, the waveform created is a train of mode locked pulses that have an optical carrier frequency chirped in time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.