Abstract A light modulator for producing a light beam having a sinusoidal intensity modulation comprising a rotating, uniaxial crystal disposed between a pair of polarizers having mutually orthogonal transmission axes. To produce a light beam having a sinusoidal intensity modulation of a substantially constant modulation frequency, an unmodulated light beam is passed through the modulator only during some portions of each revolution of the uniaxial crystal. Passage of the light beam through the modulator during the portions of each revolution of the uniaxial crystal is achieved either by an electro-optic crystal plus a polarizer located between the source of the unmodulated light beam and the polarizer nearer to the source or by a rotating, slotted cylinder encircling the rotating crystal and having the same angular velocity as the rotating crystal.
Inventors
👤 Gerald K Goldberg
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-10-27 21:17
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/28; G02B27/281
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
97 words
A light modulator for producing a light beam having a sinusoidal intensity modulation comprising first means for projecting a light beam of substantially constant amplitude along a predetermined path; a pair of polarizers positioned along said path at different distances from said first means, the transmission axis of each polarizer is oriented in a different direction; a uniaxial crystal positioned along said path intermediate said pair of polarizers; and second means coupled to said crystal for continuously rotating the optic axis of said crystal with respect to said path thereby to produce a frequency modulated light beam.
Claim 2
Dependent Claim
97 words
A light modulator for producing a light beam having a sinusoidal intensity modulation comprising first means for projecting a light beam of substantially constant amplitude along a predetermined path; a pair of polarizers positioned along said path at different distances from said first means, the transmission axis of each polarizer is oriented in a different direction; a uniaxial crystal positioned along said path intermediate said pair of polarizers; and second means coupled to said crystal for continuously rotating the optic axis of said crystal with respect to said path thereby to produce a frequency modulated light beam.
Claim 3
Dependent Claim
17 words
The light modulator according to claim 1 wherein the transmission axes of said polarizers are mutually orthogonal.
Claim 4
Dependent Claim
20 words
The light modulator according to claim 2 wherein said second means rotates said crystal at a substantially constant angular velocity.
Claim 5
Dependent Claim
59 words
The light modulator according to claim 1 further including third means having at least a component positioned along said path at a point beyond said polarizer more remote from said first means for permitting the modulated light beam to continue to propagate along said path beyond said third means only during some portions of each revolution of said crystal.