Laser communication device

• US 5,801,866 A
• Filed: 06/21/1996
• Issued: 09/01/1998
• Est. Priority Date: 08/27/1992
• Status: Expired due to Term

• Current Assignee: Trex Communications Corp. (Tortel USA LLC)
• Original Assignee: Trex Communications Corp. (Tortel USA LLC)
• Inventors: Chan, Victor, Bloom, Scott, Menders, James, Rivers, Michael
• Primary Examiner(s): Bacares, Raphael
• Application Number:
  US08/667,400
• Time in Patent Office: 802 Days
• Field of Search: 359/172, 359/159, 359/152, 359/154
• US Class Current: 398/129
• CPC Class Codes: H04B 10/11 Arrangements specific to free-space transmission, i.e. transmission through air or vacuum
• CPC Class Codes: H04B 10/1143 Bidirectional transmission
• CPC Class Codes: H04B 10/118 specially adapted for satellite communication

Abstract

A portable laser communication transceiver for transmitting and receiving information imposed on laser beams. A communication signal is imposed on a laser beam having a divergence of between 1 degree and 4 degrees. The beam is directed by an operator, sighting through a telescopic viewing device, at a distant transceiver which collects light in the laser beam with a. In preferred embodiments, the transceivers are handheld and each comprises a microphone and earphones allowing operators to talk with each other. Digital information can also be transmitted from personal computers and other electronic information equipment at the location of each operator. In a preferred embodiment useful for military and surveying applications, a GPS, a compass and a laser ranging system is provided. This enables the operator to sight through a binocular to a target and determine its position in longitude, latitude and elevation. Target position information can then be transmitted to a distant transceiver which in this case could be a base transceiver.

Claims

1. A laser communication transceiver for transmitting information via laser beams to another laser communication transceiver and for receiving information via laser beams from said another laser communication transceiver, said transceiver comprising:

A) a laser transmitter system comprising;

1) at least one laser operable to produce a signal laser beam of a selected range of wavelengths;

2) a signal modulator disposed relative to said laser and configured to modulate said signal laser beam to impose a digital communication signal on said signal laser beam;

B) a laser receiver disposed relative to said laser transmitter system and configured to receive a laser beam having a selected range of wavelengths from said another laser communication transceiver comprising;

1) an optical filter closely matched to at least one wavelength of said received laser beam,

2) a signal detector operable to receive and detect communication signals that are transmitted by said another laser communication transceiver through said optical filter;

C) a telescopic viewing device operable to locate said another similar laser communication transceiver and to facilitate pointing said transceiver in a direction of said another laser communication transceiver; and

D) a laser ranging unit, a GPS unit and an electronic compass.

2. A laser communication transceiver as in claim 1 further comprising a tilt gage.

3. A laser communication transceiver as in claim 1 further comprising a microphone and earphones.

4. A transceiver as in claim 1 further comprising a video camera and an electronic view finder.

5. A transceiver as in claim 1 further comprising a speaker.

6. A transceiver as in claim 1 wherein said laser receiver comprises a photo diode, a preamplifier, a frequency to voltage converter and a data converter for detecting said communication signal and distinguishing said signal as sound or digital data suitable for input to a computer.

7. A laser communication transceiver as in claim 1 wherein said telescopic viewing device comprises a binocular.

8. A laser communication transceiver for transmitting information via laser beams to another laser communication transceiver and for receiving information via laser beams from said another laser communication transceiver, said transceiver comprising:

A) a laser transmitter system comprising;

1) a Voight filter;

2) at least one laser disposed relative to said Voight filter and operable to produce a signal laser beam of a narrow band of wavelengths which is locked at or near 852.11 nm using said Voight filter;

3) a signal modulator disposed relative to said laser and configured to modulate said signal laser beam to impose a digital communication signal on said signal laser beam;

B) a laser receiver disposed relative to said laser transmitter system and configured to receive a laser beam having a selected range of wavelengths from said another laser communication transceiver comprising;

1) an optical filter closely matched to at least one wavelength of said received laser beam,

2) a signal detector operable to receive and detect communication signals that are transmitted by said another laser communication transceiver through said optical filter; and

C) a telescopic viewing device operable to locate said another similar laser communication transceiver and to facilitate pointing said transceiver in a direction of said another laser communication transceiver.

9. A laser communication transceiver for transmitting information via laser beams to another laser communication transceiver and for receiving information via laser beams from said another laser communication transceiver, said transceiver comprising:

A) a laser transmitter system comprising;

1) at least one laser operable to produce a signal laser beam of a selected range of wavelengths;

2) a signal modulator disposed relative to said laser and configured to modulate said signal laser beam to impose a digital communication signal on said signal laser beam;

B) a laser receiver disposed relative to said laser transmitter system and configured to receive a laser beam having a selected range of wavelengths from said another laser communication transceiver comprising;

1) an atomic line filter configured to provide a noise equivalent bandwidth of less than 0.1 nm and to have a transmission band closely matched to at least one wavelength of said received laser beam;

2) a signal detector operable to receive and detect communication signals that are transmitted by said another laser communication transceiver through said atomic line filter; and

C) a telescopic viewing device operable to locate said another similar laser communication transceiver and to facilitate pointing said transceiver in a direction of said another laser communication transceiver.

10. A laser communication transceiver as in claim 9, wherein said narrow band of wavelengths is produced with a distributed Bragg reflector laser diode with feedback control.

11. A transceiver as in claim 9 where said receiver atomic line filter is a Faraday filter.

12. A transceiver as in claim 9, wherein said receiver atomic line filter is a Voight filter.

13. A laser communication transceiver for transmitting information via laser beams to another laser communication transceiver and for receiving information via laser beams from said another laser communication transceiver, said transceiver comprising:

A) a laser transmitter system comprising;

1) a Faraday filter;

2) at least one laser disposed relative to said Faraday filter and operable to produce a signal laser beam of a narrow band of wavelengths which is locked at or near 852.11 nm using said Faraday filter;

3) a signal modulator disposed relative to said laser and configured to modulate said signal laser beam to impose a digital communication signal on said signal laser beam;

B) a laser receiver disposed relative to said laser transmitter system and configured to receive a laser beam having a selected range of wavelengths from said another laser communication transceiver comprising;

1) an optical filter closely matched to at least one wavelength of said received laser beam,

2) a signal detector operable to receive and detect communication signals that are transmitted by said another laser communication transceiver through said optical filter; and

C) a telescopic viewing device operable to locate said another similar laser communication transceiver and to facilitate pointing said transceiver in a direction of said another laser communication transceiver.