Laser line identifier

• US 4,980,554 A
• Filed: 03/31/1989
• Issued: 12/25/1990
• Est. Priority Date: 03/31/1989
• Status: Expired due to Fees

• Current Assignee: United States Of America As Represented By The Secretary Of The Army (Government of the United States of America)
• Original Assignee: The United States Of America As Represented By The Secretary Of The Army
• Inventors: Ahn, Byong H.
• Primary Examiner(s): Berman, Jack I.
• Assistant Examiner(s): HANIG, RICHARD E
• Application Number:
  US07/331,195
• Time in Patent Office: 634 Days
• Field of Search: 250/394, 250/339, 250/330, 372/29, 372/32
• US Class Current: 250/394
• CPC Class Codes: G01J 2003/123 Indexed discrete filters
• CPC Class Codes: G01J 2003/1239 and separate detectors
• CPC Class Codes: G01J 9/00 Measuring optical phase difference devices or arrangements for controlling the phase of light beams G02F1/01; Determining degree of coherence; Measuring optical wavelength spectrometry G01J3/00

Abstract

The Laser Line Identifier (LLI) is a real-time device which can indicate wavelengths of the laser radiations. LLI mainly consists of a beam splitter, narrow bandwidth transmission filters and detectors. The filters and the detectors form a unique pair so that a signal detected at a particular detector can only mean the radiation of a certain wavelength. The detectors are hardwired to a set of indicators such as a set of colored lights or a voice recording so that the wavelength of the radiation is clearly indicated even to a non-technical person.

Claims

1. A laser line identifier comprising:

a housing defining an aperture to admit laser radiation;

focussing means mounted near said aperture to focus said laser radiation into a main beam of tightly collimated radiation;

a plurality of extremely narrow pass band reflection type optical filters, each tuned to a different frequency component of said main beam and positioned to serially reflect said main beam to a terminal absorber;

a detector located behind each of said filters in the path of radiation passed by said filter; and

a primary alarm means coupled to each one of said detectors for generating a humanly perceptible signal, when said component strikes said one detector, and thereby identify the laser responsible for said component.

2. The identifier according to claim 1, further including:

a beam splitter located near said focussing means in the path of said main beam to separate said beam into a first beam of far-infrared radiation and a second beam of near visible radiation including near infrared and ultraviolet, each beam including a portion of said filters and a separate terminal absorber.

3. The identifier according to claim 1, wherein:

said terminal absorber is a wide-band detector to sense any remaining frequency components in said beam; and

a secondary alarm means to aurally announce the presence of said beam is coupled to said wide band detector.

4. The identifier according to claim 1, wherein:

said primary alarm means is a coded light source.

5. The identifier according to claim 3, wherein:

said secondary alarm means is a coded sound source.

6. The identifier according to claim 1, wherein:

said primary alarm means includes a means to play a prerecorded verbal sound message.

7. The identifier according to claim 1, wherein:

said primary alarm means includes an electronic signal generator, means to broadcast said signal over a limited range and azimuth angle and remotely located means to convert said electronic signal to said humanly perceptible signal.