Calibrated, variable output, high energy laser source

• US 7,645,982 B1
• Filed: 04/21/2009
• Issued: 01/12/2010
• Est. Priority Date: 04/21/2009
• Status: Expired due to Fees

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: King, Daniel Wayne
• Primary Examiner(s): Porta; David P
• Assistant Examiner(s): Gaworecki; Mark R
• Application Number:
  US12/427,634
• Time in Patent Office: 266 Days
• Field of Search: 250/252.1, 250/493.1, 250/503.1, 372/109
• US Class Current: 250/252.1
• CPC Class Codes: F41G 3/32 Devices for testing or checking
• CPC Class Codes: G01S 7/4972 Alignment of sensor
• CPC Class Codes: H01S 3/0014 Monitoring arrangements not otherwise provided for photometry G01J1/00, e.g. G01J1/4257; radiation pyrometry G01J5/00; measuring coherence of light G01J9/00; measuring wavelength of light G01J9/00, e.g. G01J9/0246; measuring optical pulses G01J11/00; calorimetrically measuring power of laser beams G01K17/003

Abstract

A system and method for calibrating laser designator and rangefinder test sets. The system includes a high speed detector module which receives a laser input signal, and outputs a laser output signal and an electrical pulse shaped output. A variable attenuator module receives the laser output signal and includes a rotating waveplate which rotates a polarization of the received laser output signal and a Glan laser polarizing beam splitter which receives the rotated laser output signal. The polarizing beam splitter passes only vertically polarized portions of the rotated laser output signal. An energy detector module receives the vertically polarized portions of the rotated laser output signal and includes a beam splitter which splits the vertically polarized portions of the rotated laser output signal into a first path pulse and a second path pulse. The second path pulse and the electrical pulse shaped output are used to calibrate a laser designator/rangefinder test set.

Claims

1. A system for calibrating laser designator and rangefinder test sets comprising:

a) a high speed detector module (11) which receives a laser input signal, and outputs a laser output signal (11a) and an electrical pulse shaped output (11b);

b) a variable attenuator module (15) which receives said laser output signal (11a), said variable attenuator module including;

i) a rotating waveplate (31) which rotates a polarization of the received laser output signal (11a), and

ii) a Glan laser polarizing beam splitter (35) which receives the rotated laser output signal (11a), said polarizing beam splitter passing only vertically polarized portions (15a) of said rotated laser output signal;

c) an energy detector module (17) receiving said vertically polarized portions of said rotated laser output signal and including;

a beam splitter (41) which splits said vertically polarized portions of said rotated laser output signal into a first path pulse (17c) and a second path pulse (17b), said second path pulse used to calibrate a laser designator/rangefinder test set.

2. The system defined by claim 1 where said high speed detector module (11) comprises:

a) a second beam splitter (21) which splits said laser input signal into a third path pulse and a fourth path pulse, said third path pulse corresponding to said laser output signal (11a),

b) filters and pinhole (25) into which said third path pulse is directed and output as a filtered laser signal, and

c) a high speed detector (23) which receives said filtered laser signal and outputs said electrical pulse shaped output (11b).

3. The system defined by claim 2 wherein said energy detector module further comprises:

a) a filter (44) into which the first path pulse (17c) is directed and output at a reduced power level, and

b) an energy detector (43) which receives said reduced power level output as an input and which operates to produce an energy output (17a) based on said received first path pulse.

5. The system defined by claim 1 wherein said rotation waveplate is rotated until a desired energy level is acquired which is read as an output from the energy detector module (17) based on said first path pulse (17c).

6. The system defined by claim 5 wherein said waveplate is rotated manually.

7. The system defined by claim 5 wherein said waveplate is rotated using a stepper motor.

4. A system for calibrating laser designator and rangefinder test sets comprising:

a) a high speed detector module (11) which receives a laser input signal, said module including;

i) a beam splitter (21) which splits said laser input signal into a first path pulse and a second path pulse (11a),

ii) filters and pinhole (25) into which said first path pulse is directed and output as a filtered laser signal, and

iii) a high speed detector (23) which receives said filtered laser signal and outputs an electrical pulse shaped output (11b);

b) a variable attenuator module (15) which receives said second path pulse (11a), said variable attenuator module including;

i) a rotating waveplate (31) which rotates a polarization of the received second path pulse, and

ii) a Glan laser polarizing beam splitter (35) which receives the rotated second path pulse and splits the rotated output into a third path pulse (15a) and a fourth path pulse, said polarizing beam splitter passing only vertically polarized portions of said rotated second path pulse as said third path pulse, horizontally polarized portions of said pulse shaped output being reflected inward by said polarizing beam splitter and output as said fourth path pulse to a beam dump (37);

c) an energy detector module (17) receiving said third path pulse (15a) and including;

i) a beam splitter (41) which splits said third path pulse into a fifth path pulse (17b) and a sixth path pulse (17c), said fifth path pulse (17b) being a laser output, and

ii) a filter (44) into which the sixth path pulse is directed and output at a reduced power level, and

iii) an energy detector (43) which receives said reduced power level output as an input and which operates to produce an energy output (17a) based on said received sixth path pulse;

wherein the fifth path pulse (17b) is used to calibrate a laser designator/rangefinder test set.

8. The system defined by claim 4 wherein said rotation waveplate is rotated until a desired energy level is acquired which is read as an output from the energy detector module (17) based on said sixth path pulse (17c).

9. The system defined by claim 8 wherein said waveplate is rotated manually.

10. The system defined by claim 8 wherein said waveplate is rotated using a stepper motor.

11. A method for calibrating laser designator and rangefinder test sets comprising:

a) receiving a laser input signal, and outputting a laser output signal and an electrical pulse shaped output;

b) receiving said laser output signal;

c) rotating a polarization of the received laser output signal;

d) receiving the rotated laser output signal and passing only vertically polarized portions of said rotated laser output signal;

e) receiving said vertically polarized portions of said rotated laser output signal;

f) splitting said vertically polarized portions of said rotated laser output signal into a first path pulse and a second path pulse,

g) using said second path pulse and the electrical pulse shaped output to calibrate a laser designator/rangefinder test set.

12. The method defined by claim 11 further comprising:

a) splitting said laser input signal into a third path pulse and a fourth path pulse, said third path pulse corresponding to said laser output signal,

b) outputting a filtered laser signal, and

c) receiving said filtered laser signal and outputting said electrical pulse shaped output.

13. The method defined by claim 12 further comprising

a) a filtering the first path pulse and outputting said first path pulse at a reduced power level, and

b) receiving said reduced power level output and producing an energy output based on said received first path pulse.