Diffraction encoded position measuring apparatus
When a lightwave passes through a transmission grating, diffracted beams appear at the output or opposite side of the grating that are effectively Doppler shifted in frequency (phase) whereby a detector system can compare the phase of the zero order and higher order beams to obtain an indication of position. Multiple passes through the grating increase resolution for a given wavelength of a laser signal. The resolution can be improved further by using a smaller wavelength laser to generate the grating itself. Since the grating must only have a pitch sufficient to produce diffracted orders, inexpensive, ultraviolet wavelength lasers can be utilized and still obtain high resolution detection. 3 figures.
- Research Organization:
- Rockwell International Corp
- DOE Contract Number:
- AC03-86SF16499
- Assignee:
- Rockwell International Corporation, El Segundo, CA (United States)
- Patent Number(s):
- US 5050993; A
- Application Number:
- PPN: US 7-365990
- OSTI ID:
- 7083291
- Country of Publication:
- United States
- Language:
- English
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