Patent ID: 8903245

Claim:
A method of generating an optical radiation signal, said method to be implemented by an optical radiation signal generating device that includes a dual-beam generating unit for receiving an original optical input signal and includes an optical splitter that has an input terminal and two output terminals, a phase shifter, and two optical circulators, and a second-order fiber Bragg grating (FBG) having opposite first and second ends, the method comprising the following steps of: a) configuring the dual-beam generating unit to generate, from the original optical input signal, first and second optical input signals, which have a phase difference therebetween, according to a control signal; and b) configuring the second-order FBG to receive the first and second optical input signals, respectively, through the first and second ends thereof, to generate first and second optical output signals according to the first and second optical input signals, and to radiate an optical radiation signal, which is to be received by a wireless receiver, by interference between the first and second optical input signals: wherein, in step a): the optical splitter is configured to receive the original optical input signal through the input terminal, to split the original optical input signal into first and second optical signals, and to output the first and second optical signals through the output terminals, respectively; the phase shifter is configured to receive the first optical signal and to shift phase of the first optical signal according to the control signal so as to output a phase-shifted first optical signal; and the optical circulators are configured to receive the phase-shifted first optical signal and the second optical signal, and to output the first and second optical input signals based on the phase-shifted first optical signal and the second optical signal, respectively; and wherein, in step b), the first and second optical output signals are emitted respectively from the first and second ends along an imaginary line extending from the first end to the second end, and the optical radiation signal is radiated in a radial direction perpendicular to the imaginary line.