US4425648A — Wavelength selectivity of lasers and control ther…

Claim 1

Independent Claim 147 words

A frequency-selective laser system, comprising: an optical laser cavity; a primary reflector serving as a first boundary of said optical laser cavity; a plurality of wavelength-selective gratings, each one tuned for reflecting radiation of a single wavelength and wherein each grating also serves as a boundary for said optical laser cavity; means for extracting radiation wherein said means comprises said primary reflector or said wavelength-selective gratings; an active region containing an active medium capable of lasing at more than one wavelength, being positioned between said primary reflector and said wavelength-selective gratings; an adjustable mirror being positioned between said active region and said gratings, to provide an optical path for each of said wavelength-selective gratings; and adjusting means for pivoting said adjustable mirror wherein, in recited sequence, said primary reflector, said active region, said adjustable mirror, and each of said wavelength-selective gratings in turn, are in optical alignment.

Claim 2

Dependent Claim 147 words

A frequency-selective laser system, comprising: an optical laser cavity; a primary reflector serving as a first boundary of said optical laser cavity; a plurality of wavelength-selective gratings, each one tuned for reflecting radiation of a single wavelength and wherein each grating also serves as a boundary for said optical laser cavity; means for extracting radiation wherein said means comprises said primary reflector or said wavelength-selective gratings; an active region containing an active medium capable of lasing at more than one wavelength, being positioned between said primary reflector and said wavelength-selective gratings; an adjustable mirror being positioned between said active region and said gratings, to provide an optical path for each of said wavelength-selective gratings; and adjusting means for pivoting said adjustable mirror wherein, in recited sequence, said primary reflector, said active region, said adjustable mirror, and each of said wavelength-selective gratings in turn, are in optical alignment.

Claim 3

Dependent Claim 106 words

A laser, having a resonant, optical laser cavity defined by a wavelength-selective boundary, comprising: an active region containing an active medium capable of lasing at more than one wavelength; a primary reflector disposed so as to form a second boundary of said laser cavity; an adjustable mirror disposed so as to receive radiation from said active region; a plurality of different wavelength-selective gratings disposed to receive the reflection from said adjustable mirror and disposed to form said wavelength-selective boundary of said laser cavity; and adjusting means for maintaining adjustable mirror in optical alignment with said primary reflector, said active region, and one of said wavelength-selective gratings.

Claim 4

Dependent Claim 106 words

A laser, having a resonant, optical laser cavity defined by a wavelength-selective boundary, comprising: an active region containing an active medium capable of lasing at more than one wavelength; a primary reflector disposed so as to form a second boundary of said laser cavity; an adjustable mirror disposed so as to receive radiation from said active region; a plurality of different wavelength-selective gratings disposed to receive the reflection from said adjustable mirror and disposed to form said wavelength-selective boundary of said laser cavity; and adjusting means for maintaining adjustable mirror in optical alignment with said primary reflector, said active region, and one of said wavelength-selective gratings.

Claim 5

Dependent Claim 55 words

The laser of claims 1 or 2 wherein said adjusting means comprises: an electric drive for pivoting said adjustable mirror into more than one position, wherein each mirror position corresponds to a wavelength-selective grating; and circuit means for providing electrical signals to said electric drive, establishing a timed sequence of pivoting of said adjustable mirror.

Claim 6

Dependent Claim 40 words

The laser of claim 3 wherein said circuit means is a staircase generator, the particular signals being of a staircase contour and operating to stepwise position the mirror in the angular position for stepwise changing frequency selectivity of the laser.

Claim 7

Dependent Claim 43 words

The laser of claim 3 wherein said circuit means includes a feedback device operatively connected to said adjustable mirror wherein said feedback device serves as a position refinement means for stabilizing the position of the adjustable mirror in relation to said wavelength-selective gratings.

Claim 8

Dependent Claim 140 words

The laser of claims 1 or 2 further including an adjustable mirror feedback system comprising: a plurality of reference mirrors for insuring adaptable mirror and wavelength-selective grating alignment; a feedback reflector coupled to said adjustable mirror; optical means for directing a beam of radiation onto said feedback reflector wherein said optical means, said feedback reflector, and one of the plurality of said reference mirrors are in optical alignment, and wherein the optical alignment of each of said reference mirrors corresponds to the alignment of one of said wavelength-selective gratings; detection means disposed for detecting any misalignment of said optical means, said feedback reflector, and each of said reference mirrors and to provide an electrical signal representative thereof; and said adjusting means further including electrical drive means for said adjustable mirror connected so as to be responsive to said electrical signal.

Claim 9

Dependent Claim 25 words

The laser of claim 6 wherein said electrical signal is a staircase signal for sequentially obtaining the alignment corresponding to each of said reference mirrors.

Claim 10

Dependent Claim 47 words

The laser of claim 6, including means for temporarily suppressing said electrical signal upon changing said electrical drive means so that feedback control for stabilizing the position of the adjustable mirror is interrupted while the adjustable mirror is adjusted to a position different from a previous position.

Claim 11

Dependent Claim 33 words

The laser of claims 1 or 2 further including control means for precision-tuning the optical cavity, as defined by said first reflector and individual wavelength-selective gratings, following each adjustment of said adjustable mirror.

Claim 12

Dependent Claim 16 words

The laser of claim 1 wherein said control means includes means for dithering said primary reflector.

Claim 13

Dependent Claim 109 words

Apparatus for measuring the optical gain or loss of a beam of radiation at different wavelengths, comprising: a laser having a primary reflector, an active laser region and a plurality of wavelength-selective gratings, said primary reflector and said wavelength-selective gratings defining an optical resonant cavity, wherein either said primary reflector or one of said wavelength-selective gratings serve as an output coupler for extracting radiation, and directing said radiation toward a test medium; detector means for measuring any gain or loss of beam energy after having passed through said test medium; and means for changing the position of said adjustable mirror in order to obtain different wavelengths for the beam.

Claim 14

Dependent Claim 109 words

Apparatus for measuring the optical gain or loss of a beam of radiation at different wavelengths, comprising: a laser having a primary reflector, an active laser region and a plurality of wavelength-selective gratings, said primary reflector and said wavelength-selective gratings defining an optical resonant cavity, wherein either said primary reflector or one of said wavelength-selective gratings serve as an output coupler for extracting radiation, and directing said radiation toward a test medium; detector means for measuring any gain or loss of beam energy after having passed through said test medium; and means for changing the position of said adjustable mirror in order to obtain different wavelengths for the beam.

Claim 15

Dependent Claim 39 words

Apparatus of claim 11, wherein said adjusting means comprises an electric drive for pivoting said adjustable mirror into more than one position corresponding each of said wavelength-selective gratings, and circuit means for providing electrical signals to said electric drive.

Claim 16

Dependent Claim 42 words

Apparatus as in claim 11 wherein said circuit means includes a feedback device operatively connected to said adjustable mirror wherein said feedback device serves as a position refinement means for stabilizing the position of the adjustable mirror in relation to said gratings.

Claim 17

Dependent Claim 31 words

Apparatus as in claim 11 further including control means for precision-tuning the optical cavity, as defined by said first reflector and individual wavelength-selective gratings, following each adjustment of said adjustable mirror.

Claim 18

Dependent Claim 134 words

Method of measuring the optical energy gain or loss in a test medium at different wavelengths, comprising the steps of: positioning a laser so that its output beam traverses said test medium, and wherein said laser further comprises an optical cavity and an active region lasing at a plurality of wavelengths, the cavity being bounded at one end by one of a plurality of wavelength-selective gratings, there being an adjustable mirror for sequentially selecting each of said wavelength-selective gratings, and at the other end by a primary reflector and wherein said output beam of said laser provides a beam comprised of a series of wavelengths substantially similar to the different wavelengths of the test medium; and comparing beam energy after having traversed said test medium with beam energy prior to traversing said test medium.

Claim 19

Dependent Claim 134 words

Method of measuring the optical energy gain or loss in a test medium at different wavelengths, comprising the steps of: positioning a laser so that its output beam traverses said test medium, and wherein said laser further comprises an optical cavity and an active region lasing at a plurality of wavelengths, the cavity being bounded at one end by one of a plurality of wavelength-selective gratings, there being an adjustable mirror for sequentially selecting each of said wavelength-selective gratings, and at the other end by a primary reflector and wherein said output beam of said laser provides a beam comprised of a series of wavelengths substantially similar to the different wavelengths of the test medium; and comparing beam energy after having traversed said test medium with beam energy prior to traversing said test medium.

Claim 20

Dependent Claim 44 words

Method as in claim 15 wherein comparing beam energy includes the step of permitting said beam to pass through said test medium and alternatingly inhibiting such passage for detecting reference values between each detecting of the beam as having passed through the test medium.

Claim 21

Dependent Claim 32 words

Method as in claim 15 wherein said pivoting step includes a stepwise change of said adjustable mirror to sequentially couple one of said wavelength-selective gratings after the other to said active region.

Claim 22

Dependent Claim 24 words

Method as in claim 17 including the step of adjusting the length of the optical cavity after each change in said adjustable mirror position.

Claim 23

Dependent Claim 22 words

Method as in claims 15 or 18, said test medium being a plasma of a gas dynamic laser also having said wavelengths.

Claim 24

Dependent Claim 25 words

Method as in claim 17 including the step of attuning said pivoting step by providing a feedback signal to more precisely position said adjustable mirror.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1987-01-09	1987-07-11	1988-01-10	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1991-01-09	1991-07-11	1992-01-10	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1995-01-09	1995-07-11	1996-01-10	$7700.00	Window Closed / Lapsed

Wavelength selectivity of lasers and control thereof for rapid action measuring tasks

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag