Optics: measuring and testing – Range or remote distance finding – With photodetection
Patent
1986-05-08
1989-03-28
Corbin, John K.
Optics: measuring and testing
Range or remote distance finding
With photodetection
35016223, 350320, 356334, 372 20, G02B 2744, G01J 318, H01S 310
Patent
active
048158208
ABSTRACT:
A method and improved apparatus for aligning a diffraction grating, as, for example, one used in tuning the output of a laser. The total angular misalignment .epsilon. between the incident and diffracted beams is a function of three angles: the tuning angle .theta.16, the angle of tilt .beta. between the plane of the grating 15 and the tuning rotational axis, and the angle .alpha. between the grating lines and the projection of the turning rotational axis in the plane of the grating 15. The present invention provides a method of aligning the diffraction grating so that the residual alignment error is very small over the desired range of tuning angle .theta. 16, by adjusting only .alpha. or only .beta. to zero at two reference tuning angles .theta..sub.0 and .theta..sub.1. Knowledge of the value of either .alpha. or .beta. is not necessary. For a CO.sub.2 laser tuned over the wavelength range 9.11 to 10.88 .mu.m, calculations show that the present method grating alignment results in a residual angular misalignment error .epsilon. of less than 60 .mu.rads, when .alpha. is close to 12,000 .mu.rads and .beta. is equal to 10,000 .mu.rads. Since adjustment of only .alpha. or .beta. is necessary in minimizing the total misalignment, an improved apparatus for aligning diffraction gratings consists of providing means for adjusting only one of the two angles .alpha. and .beta. in addition to the tuning angle .theta..
REFERENCES:
patent: Re27653 (1973-05-01), Oskam
patent: 3775010 (1973-11-01), Chupp et al.
patent: 4639081 (1987-01-01), O'Brien
(S16310012) Bergstrom, G., et al., "A Fast Method for Calibrating Cosecant Drive Monochromators", Journal of Roman Spectroscopy, vol. 9, No. 6, Dec. 1980, pp. 403-406.
(S01980039) Aspnes, D. et al., "Geometrically Exact Monochromator Alignment", Rev. Sci. Instrum, vol. 41, No. 7, Jul. 1970, pp. 966-968.
(S86960037G) Hallgren, R. "Application of a Holographically Recorded Concave Diffraction Grating in a Single--Beam Spectrophotometer", American Laboratory, vol. 9, No. 11, Nov. 1977, pp. 69-75.
McNeil John A.
Reeder Robin A.
Corbin John K.
Edmondson David J.
Hughes Aircraft Company
Karambelas A. W.
Streeter William J.
LandOfFree
Method and apparatus for aligning a diffraction grating for tuni does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for aligning a diffraction grating for tuni, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for aligning a diffraction grating for tuni will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1654699