System for optical wireless power supply

• US 9,866,075 B2
• Filed: 04/11/2017
• Issued: 01/09/2018
• Est. Priority Date: 04/11/2016
• Status: Active Grant

• Current Assignee: Wi-Charge Ltd.
• Original Assignee: Wi-Charge Ltd.
• Inventors: Slepoy, Alexander, Golan, Lior, Nahmias, Omer, Sagi, Ran, Alpert, Ortal, Mor, Ori Refael
• Primary Examiner(s): Barnie, Rexford
• Assistant Examiner(s): Ortiz, Elim
• Application Number:
  US15/484,722
• Publication Number:
  US 20170294809A1
• Time in Patent Office: 273 Days
• CPC Class Codes: H01L 31/0304 including, apart from doping materials or other impurities, only AIIIBV compounds
• CPC Class Codes: H01S 3/0071 Beam steering, e.g. whereby a mirror outside the cavity is present to change the beam direction
• CPC Class Codes: H01S 3/1022 by controlling the optical pumping
• CPC Class Codes: H02J 50/30 using light, e.g. lasers
• CPC Class Codes: H02J 7/35 with light sensitive cells
• CPC Class Codes: H04B 10/807 Optical power feeding, i.e. transmitting power using an optical signal
• CPC Class Codes: Y02E 10/544 Solar cells from Group III-V materials

Abstract

A system incorporating safety features, for optical power transmission to receivers, comprising an optical resonator having end reflectors and a gain medium, a driver supplying power to the gain medium, and controlling its small signal gain, a beam steering apparatus and a controller to control at least the beam steering apparatus and the driver. The controller responds to a safety risk occurring in the system, by outputting a command to change at least some of the small signal gain of the gain medium, the radiance of the optical beam, the power supplied by the driver, the scan speed or the scan direction and position of the beam steering apparatus, or to register the scan pose which defines the location of said optical-to-electrical power converter. The controller may also ensure a high overall radiance efficiency, and may warn of transmitted power not received by a targeted receiver.

Claims

1. A system for optical wireless power transmission to at least one power receiving apparatus, said system comprising:

an optical resonator having end reflectors and adapted to emit an optical beam;

a gain medium comprising either (i) a semiconductor device, or (ii) a solid host doped with neodymium ions and in optical communication with a filter attenuating radiation for at least one frequency having a wave number in the range 8,300 cm−

1 to 12,500 cm−

1, said gain medium being positioned inside said optical resonator and having a first bandgap energy, said gain medium being thermally attached to a cooling system and configured to amplify light passing through it;

a driver configured to supply power to said gain medium, and enabling control of the small signal gain of said gain medium;

a beam steering apparatus configured to direct said optical beam in at least one of a plurality of directions;

an optical-to-electrical power converter located in said at least one power receiving apparatus and configured to convert said optical beam into electrical power having a voltage, said optical-to-electrical power converter having a second bandgap energy;

a detector configured to provide a signal indicative of said optical beam impinging on said optical-to-electrical power converter;

a voltage converter connected to the output of said optical-to-electrical power converter, said voltage converter comprising an inductor having an inductance between

2. A system according to claim 1 wherein said voltage converter is configured to track the maximum power point of said optical-to-electrical power converter.

3. A system according to claim 1 wherein said voltage converter is a DC/DC boost voltage converter.

4. A system according to claim 1, wherein said resonator comprises at least one dielectric mirror.

5. A system according to claim 1, wherein said optical-to-electrical power converter is a photovoltaic cell.

6. A system according to claim 5 wherein said photovoltaic cell comprises a III-V semiconductor material.

7. A system according to claim 1, further including an inductor and an energy storage device that may be a capacitor or a rechargeable battery.

8. A system according to claim 1, wherein said system is configured to receive information from said power receiving apparatus.

9. A system according to claim 8 wherein said information includes at least one of battery status, device identification, power needs, voltage needs and a key.

10. A system according to claim 1, further comprising a sensor for determining the temperature of said optical-to-electrical power converter.

11. A system according to claim 10 configured to modify the power of said optical beam in response to changes in said temperature of said optical-to-electrical power converter.

12. A system according to claim 1, further comprising an optical window positioned between said photovoltaic optical-to-electrical power converter and said beam steering apparatus, said window having a refractive index of at least 1.5.

13. A system according to claim 1, wherein said second bandgap energy is smaller than said first bandgap energy.

14. A system according to claim 1, wherein said controller is adapted such that said beam steering apparatus directs said optical beam onto said at least one power receiving apparatus.

15. A system for optical wireless power transmission to at least one power receiving apparatus, said system comprising:

an optical resonator having end reflectors and adapted to emit an optical beam;

a gain medium comprising either a semiconductor device or a solid host doped with Neodymium ions and in optical communication with a filter attenuating radiation for at least one frequency having a wave number in the range 8,300 cm−

1 to 12,500 cm—

1, said gain medium being positioned inside said optical resonator and having a first bandgap energy, said gain medium being thermally attached to a cooling system and configured to amplify light passing through it;

a driver configured to supply power to said gain medium, and enabling control of the small signal gain of said gain medium;

a beam steering apparatus configured to direct said optical beam in at least one of a plurality of directions;

an optical-to-electrical power converter located in said at least one power receiving apparatus, and configured to convert said optical beam into electrical power having a voltage, said optical-to-electrical power converter having a second bandgap energy;

a detector configured to provide a signal indicative of said optical beam impinging on said optical-to-electrical power converter;

a voltage converter connected to the output of said optical-to-electrical power converter, said voltage converter comprising an inductor having an inductance between

16. A system according to claim 15 wherein said indication of a safety risk occurring in the system is obtained at least from said signal generated by said detector configured to provide a signal indicative of said optical beam impinging on said optical-to-electrical power converter, and from a signal generated by the level received at said resonator of said beam reflected from said at least one power receiving apparatus.

17. A system according to claim 15 wherein said voltage converter is configured to track the maximum power point of said optical-to-electrical power converter.

18. A system according to claim 15 wherein said voltage converter is a DC/DC boost voltage converter.

19. A system according to claim 15 wherein said optical-to-electrical power converter is a photovoltaic cell.

20. A system according to claim 19 wherein said photovoltaic cell comprises a III-V semiconductor material.

21. A system according to claim 15, further including an energy storage device that may be a capacitor or a rechargeable battery.

22. A system according to claim 15, wherein said system is configured to receive information from said at least one power receiving apparatus said information including at least one of battery status, device identification, power needs, voltage needs and a key.

23. A system according to claim 15, further comprising a sensor for determining the temperature of said optical-to-electrical power converter.

24. A system according to claim 23, said system configured to modify the power of said optical beam in response to changes in said temperature of said optical-to-electrical power converter.

25. A system according to claim 15, further comprising an optical window positioned between said photovoltaic optical-to-electrical power converter and said beam steering apparatus, said window having a refractive index of at least 1.5.

26. A system according to claim 15, wherein said second bandgap energy is smaller than said first bandgap energy.