Coherent light generators – Particular beam control device – Optical output stabilization
Patent
1995-01-06
1996-09-03
Bovernick, Rodney E.
Coherent light generators
Particular beam control device
Optical output stabilization
372 35, 372 38, 331 3, 331 941, H01S 3133, H03L 726
Patent
active
055530877
ABSTRACT:
A laser diode has its frequency locked to the frequency of an absorption line of rubidium (water and oxides of nitrogen are also disclosed). The level of absorption, and hence the frequency relationship of the laser light with respect to the absorption line is detected by a photodetector. The absolute frequency of the laser light is guaranteed by initially adjusting the temperature of the diode until the frequency of the light is brought into coincidence with a first absorption line, subsequently maintaining the temperature at a constant level, and adjusting the drive current of the diode until the frequency of laser light achieves coincidence with an adjacent transition line. This ensures that the diode frequency is locked to the same absorption line each occasion the diode is switched on. Additionally, the change in drive current between coincidence with the two adjacent absorption lines is monitored as a further check that the correct transition line has been selected. An error signal for a current servo, which drives the diode, is generated from the photodetector output. An oscillating magnetic field, causing cyclic Zeeman splitting of the absorption lines, and hence cyclic modulation of their frequency, causes a corresponding modulation in the photodetector output. Successive half cycles of the photodetector output are integrated and subtracted from each other in order to generate the error signal; the sign of the error signal thus being indicative of the direction of frequency drift in the laser light.
REFERENCES:
patent: 4410273 (1983-10-01), Mantz et al.
patent: 4509130 (1985-04-01), Menzies et al.
patent: 4701607 (1987-10-01), El Hanany et al.
patent: 4833681 (1989-05-01), Akiyama et al.
patent: 4922480 (1990-05-01), Bosch
patent: 5025448 (1991-06-01), Sudo et al.
patent: 5063568 (1991-11-01), Chiba et al.
patent: 5185643 (1993-02-01), Vry et al.
R. A. Valenzuela et al., "Frequency Stabilisation of AlGaAs Lasers to Absorption Spectrum of Rubidium Using Zeeman Effect," Electronics Letters, Jun. 9, 1988, vol. 24, No. 12, pp. 725-726.
M. Tetu et al., "Multiwavelength Sources Using Laser Diodes Frequency-Locked to Atomic Resonances," Journal of Lightwave Technology, vol. 7, No. 10, Oct. 1989, pp. 1540-1547.
H. Wolfelschneider et al., "Intensity-Indpendent Frequency Stabilization of Semiconductor Lasers Using a Fiber Optic Fabry-Perot Resonator," Journal of Optical Communications, 5 (1984) Jun., No. 2, Berlin, Germany, pp. 53-55.
Woan-Hue Hong et al., "Simultaneously Stabilization of the Frequency and Output Power of Semiconductor Laser for Coherent Optical Fiber Communication Systems," Proceedings TENCON 87, v. 2, Aug. 25-28, 1987, Seoul, Korea, pp. 739-743.
Bovernick Rodney E.
McNutt Robert
Renishaw plc
LandOfFree
Frequency stabilized laser diode does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Frequency stabilized laser diode, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Frequency stabilized laser diode will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1957232