United States Patent
US Patent 5808743: Laser sensor using optical feedback-induced…
US 5808743 · granted 1998-09-15
Abstract
This invention provides an inexpensive, sensitive sensor to measure target position, velocity and vibration based on optical feedback-induced fluctuations in the operating frequency of a diode laser. The sensor comprises a diode laser, an optical frequency discriminator to measure the laser operating frequency, and an electronic signal analyzer to obtain the modulation frequency of the laser operating frequency. This invention further includes two calibration mechanisms for vibration amplitude measurement. In a first calibration mechanism the diode laser is mounted on a laser vibrator, which vibrates the laser relative to the target. In a second calibration mechanism a frequency modulator is coupled to the diode laser to modulate the operating frequency.
| Patent Number | 5808743 |
|---|---|
| Title | Laser sensor using optical feedback-induced frequency modulation |
| Filed | 1996-04-05 |
| Granted | 1998-09-15 |
| Inventor(s) | Cornell; Eric A., Roos; Peter A., Stephens; Michelle S. E., Wieman; Carl E. |
| Assignee | Board of Regents of the University of Colorado |
| Number of Claims | 68 |
Abstract
This invention provides an inexpensive, sensitive sensor to measure target position, velocity and vibration based on optical feedback-induced fluctuations in the operating frequency of a diode laser. The sensor comprises a diode laser, an optical frequency discriminator to measure the laser operating frequency, and an electronic signal analyzer to obtain the modulation frequency of the laser operating frequency. This invention further includes two calibration mechanisms for vibration amplitude measurement. In a first calibration mechanism the diode laser is mounted on a laser vibrator, which vibrates the laser relative to the target. In a second calibration mechanism a frequency modulator is coupled to the diode laser to modulate the operating frequency.
Claim 1
A sensor for measuring a target comprising: a diode laser having an unperturbed wavelength .lambda..sub.o and a laser operating frequency .omega., said frequency .omega. subject to perturbation by optical feedback from the target; an optical frequency discriminator, optically coupled with said diode laser, for generating an electronic signal representative of .omega.; an electronic signal analyzer for receiving said electronic signal and for determining a first modulation frequency .omega..sub.f of said laser operating frequency .omega.; and a laser vibrator, mechanically coupled with said diode laser, for vibrating said diode laser at laser vibration frequency .omega..sub.L with vibration amplitude b.sub.L.
Claims
68 totalA sensor for measuring a target comprising: a diode laser having an unperturbed wavelength .lambda..sub.o and a laser operating frequency .omega., said frequency .omega. subject to perturbation by optical feedback from the target; an optical frequency discriminator, optically coupled with said diode laser, for generating an electronic signal representative of .omega.; an electronic signal analyzer for receiving said electronic signal and for determining a first modulation frequency .omega..sub.f of said laser operating frequency .omega.; and a laser vibrator, mechanically coupled with said diode laser, for vibrating said diode laser at laser vibration frequency .omega..sub.L with vibration amplitude b.sub.L.