Patent ID: 9742223
Date: 2017-08-22
CPC Classifications: H02J,H04B

Claim:
1. A system for optical wireless power transmission to at least one power receiving apparatus comprising: an optical resonator having end reflectors and adapted to emit an optical beam; a gain medium positioned inside said optical resonator, said gain medium having a first bandgap energy, and said gain medium being configured to amplify light passing through it; a driver supplying power to said gain medium, and effecting a 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 at least one of said 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; an electrical voltage converter, adapted to convert the voltage of said electrical power generated by said optical-to-electrical power converter into a different voltage, said electrical voltage converter comprising an inductor, an energy storage device and a switch; at least one surface associated with said optical-to-electrical power converter traversed by said optical beam, a detector configured to provide a signal indicative of said optical beam impinging on said at least one receiving apparatus; and a controller adapted to control at least one of the status of said beam steering apparatus and said driver, said controller receiving a control input signal from at least said detector, wherein: said at least one surface having properties such that it reflects a small part of light incident on it, either (i) diffusively, or (ii) such that said reflected light has a virtual focus positioned remotely from said optical resonator relative to said surface, or (iii) such that said reflected light has a real focus positioned at least 1 cm from said surface; said controller is configured to respond to said control input signal received from said detector by at least one of: causing said driver to change the small signal gain of the gain medium; changing the radiance of said optical beam; changing the power supplied by said driver; changing the scan speed of said beam steering apparatus; changing the scan position of said beam steering apparatus; and recording a scan position defining the position of said optical-to-electrical power converter; said gain medium is either a semiconductor device or a solid host doped with Nd ions said second bandgap energy is smaller than said first bandgap energy; said first bandgap energy is between 0.8 eV and 1.1 eV; said switch has a closed serial resistance smaller than R, given by the equation where R is measured in Ohms, E P said optical beam has a frequency between the first overtone of the C—H absorption situated at approximately 6940 cm