LASER LIGHT TRANSCEIVER AND LASER RADAR DEVICE

• US 20170242100A1
• Filed: 08/12/2014
• Published: 08/24/2017
• Est. Priority Date: 08/12/2014
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: HINOKUMA, Yasuhiro, SAKIMURA, Takeshi, AKINO, Yosuke, YANAGISAWA, Takayuki, TANAKA, Hisamichi
• Granted Patent: US 10,353,054 B2
• Time in Patent Office: Days
• CPC Class Codes: G01C 3/06 Use of electric means to obtain final indication
• CPC Class Codes: G01S 17/58 Velocity or trajectory determination systems; Sense-of-movement determination systems
• CPC Class Codes: G01S 17/95 for meteorological use
• CPC Class Codes: G01S 7/4811 common to transmitter and receiver
• CPC Class Codes: G01S 7/4812 transmitted and received beams following a coaxial path
• CPC Class Codes: G01S 7/4817 relating to scanning
• CPC Class Codes: G01S 7/4818 using optical fibres
• CPC Class Codes: G01S 7/4917 superposing optical signals in a photodetector, e.g. optical heterodyne detection
• CPC Class Codes: G01S 7/499 using polarisation effects
• CPC Class Codes: Y02A 90/10 Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

Disclosed is a laser light transceiver which is configured so as to include a polarization changing unit 2 for outputting a laser light beam outputted from a transmission light source 1 toward a direction corresponding to the polarization of the laser light beam while changing the polarization of the laser light beam with respect to time. As a result, the laser light transceiver can transmit a laser light beam, whose power is not decreased, in two eye directions without mechanically scanning with the laser light beam.

Claims

1. A laser radar device comprising:

a light source to output a laser light beam;

a polarization changing unit to output said laser light beam toward a direction corresponding to polarization of said laser light beam while changing the polarization of said laser light beam outputted from said light source with respect to time;

a first transmission and reception optical system to emit the laser light beam outputted from said polarization changing unit into space, and receiving a reflected light beam of said laser light beam, the reflected light beam being reflected by an observation target existing in the space;

a second transmission and reception optical system disposed in a direction different from that in which said first transmission and reception optical system is disposed, to emit the laser light beam outputted from said polarization changing unit into the space, and receive a reflected light beam of said laser light beam, the reflected light beam being reflected by an observation target existing in the space;

a reception optical system to receive the reflected light beam received by said first transmission and reception optical system, and also receive the reflected light beam received by said second transmission and reception optical system; and

a heterodyne detecting unit to combine each of the reflected light beams received by said reception optical system, and a local light beam corresponding to the laser light beam outputted from said light source, to acquire beat signals,

wherein said heterodyne detecting unit includes;

a reflected light beam switching unit to output the reflected light beams received by said reception optical system toward directions corresponding to polarization directions of said reflected light beams;

a local light beam switching unit to output the local light beam corresponding to the laser light beam toward a direction corresponding to polarization of said local light beam while changing the polarization of said local light beam outputted from said light source with respect to time;

a first heterodyne detecting unit to combine one of the reflected light beams outputted from said reflected light beam switching unit and the local light beam outputted from said local light beam switching unit, to acquire a beat signal; and

a second heterodyne detecting unit disposed in a direction different from that in which said first heterodyne detecting unit is disposed, to combine another of the reflected light beams outputted from said reflected light beam switching unit and the local light beam outputted from said local light beam switching unit, to acquire a beat signal.

2. The laser radar device according to claim 1, wherein said polarization changing unit comprises:

a polarization changing device to change the polarization of the laser light beam outputted from said light source with respect to time, and

a polarizer to output said laser light beam to either said first transmission and reception optical system or said second transmission and reception optical system in accordance with the polarization changed by said polarization changing device.

3. The laser radar device according to claim 2, wherein said polarizer reflects the reflected light beams received by said first and second transmission and reception optical systems toward a direction in which said reception optical system is disposed.

4. A laser radar device comprising:

a light source to output a laser light beam;

a polarization changing unit to output said laser light beam toward a direction corresponding to polarization of said laser light beam while changing the polarization of said laser light beam outputted from said light source with respect to time;

a first transmission and reception optical system to emit the laser light beam outputted from said polarization changing unit into space, and receive a reflected light beam of said laser light beam, the reflected light beam being reflected by an observation target existing in the space;

a second transmission and reception optical system disposed in a direction different from that in which said first transmission and reception optical system is disposed, to emit the laser light beam outputted from said polarization changing unit into the space, and receive a reflected light beam of said laser light beam, the reflected light beam being reflected by an observation target existing in the space;

a reception optical system to receive the reflected light beam received by said first transmission and reception optical system, and also receive the reflected light beam received by said second transmission and reception optical system; and

a heterodyne detecting unit to combine each of the reflected light beams received by said reception optical system, and a local light beam corresponding to the laser light beam outputted from said light source, to acquire beat signals,

wherein said heterodyne detecting unit includes;

a reflected light beam switching unit to output the reflected light beams received by said reception optical system toward directions corresponding to polarization directions of said reflected light beams;

a local light beam splitting unit to split the local light beam corresponding to the laser light beam outputted from said light source into beams in two directions;

a first heterodyne detecting unit to combine one of the reflected light beams outputted from said reflected light beam switching unit and a local light beam which is one of the beams split by said local light beam splitting unit, to acquire a beat signal; and

a second heterodyne detecting unit to combine another of the reflected light beams outputted from said reflected light beam switching unit and a local light beam which is another of the beams split by said local light beam splitting unit, to acquire a beat signal.

10. The laser radar device according to claim 4, wherein said polarization changing unit comprises:

a polarization changing device to change the polarization of the laser light beam outputted from said light source with respect to time, and

a polarizer to output said laser light beam to either said first transmission and reception optical system or said second transmission and reception optical system in accordance with the polarization changed by said polarization changing device.

11. The laser radar device according to claim 10, wherein said polarizer reflects the reflected light beams received by said first and second transmission and reception optical systems toward a direction in which said reception optical system is disposed.

5-6. -6. (canceled)

7. A laser radar device comprising:

a light source to output a laser light beam;

a polarization changing unit to output said laser light beam toward a direction corresponding to polarization of said laser light beam while changing the polarization of said laser light beam outputted from said light source with respect to time;

a first transmission and reception optical system to emit the laser light beam outputted from said polarization changing unit into space, and receive a reflected light beam of said laser light beam, the reflected light beam being reflected by an observation target existing in the space;

a second transmission and reception optical system disposed in a direction different from that in which said first transmission and reception optical system is disposed, to emit the laser light beam outputted from said polarization changing unit into the space, and receive a reflected light beam of said laser light beam, the reflected light beam being reflected by an observation target existing in the space;

a reception optical system to receive the reflected light beam received by said first transmission and reception optical system, and also receive the reflected light beam received by said second transmission and reception optical system; and

a heterodyne detecting unit to combine each of the reflected light beams received by said reception optical system, and a local light beam corresponding to the laser light beam outputted from said light source, to acquire beat signals,

wherein said heterodyne detecting unit includes;

a local light beam switching unit to change polarization of the local light beam corresponding to the laser light beam outputted from said light source with respect to time; and

a heterodyne detector to combine each of the reflected light beams received by said reception optical system and the local light beam whose polarization is changed with respect to time by said local light beam switching unit, to acquire beat signals.

8. The laser radar device according to claim 7, wherein said polarization changing unit comprises:

a polarization changing device to change the polarization of the laser light beam outputted from said light source with respect to time, and

a polarizer to output said laser light beam to either said first transmission and reception optical system or said second transmission and reception optical system in accordance with the polarization changed by said polarization changing device.

9. The laser radar device according to claim 8, wherein said polarizer reflects the reflected light beams received by said first and second transmission and reception optical systems toward a direction in which said reception optical system is disposed.