Low-loss high-repetition-rate pulsed laser modulator

Abstract

The present invention provides a low-loss high-repetition-rate pulsed laser modulator comprising: a 2*2, 1:1 coupler; a light delay module; a 1*2, 1:1 coupler. The present invention can modulate a low-repetition-rate pulsed laser to be a high-repetition-rate pulsed laser. The basic principle is: one beam of low-repetition-rate pulsed laser can be divided into two beams with the same light intensity by a 1*2, 1:1 coupler; control the two beams of light to have an optical path difference so that when they are coupled into a 2*2, 1:1 coupler, a double pulse repetition rate can be obtained; In the same way, when the two beams of light from former 2*2, 1:1 coupler, with another different optical path difference are coupled into the next 2*2, 1:1 coupler, a double pulse repetition rate can be obtained again; when we obtain the repetition rate we need, a 1*2, 1:1 coupler instead is connected to couple the two beams of light into one beam with a double repetition rate.

Claims

1. A low-loss high-repetition-rate pulsed laser modulator comprising: two 1*2, 1:1 couplers configured as an input end and an output end of the modulator respectively; at least two light delay modules arranged on a same light path between the two 1*2, 1:1 couplers; and at least one 2*2, 1:1 coupler with each arranged between two adjacent light delay modules; wherein the light delay modules are configured to control path-length difference l according to the following formula: $l=\left(\mathrm{kt}+\frac{t}{2}\right).Math.\frac{c}{n};$ where, c is a velocity of light in vacuum, n is a refractive index of fibers, k is a natural number, and t is time difference between two neighboring pulses respectively transmitted in two light paths.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 illustrates an embodiment of the high-repetition-rate pulsed laser modulator according the present invention, wherein: 1: 1*2, 1:1 coupler; 2: light delay module; 3: 2*2, 1:1 coupler; 4: light delay module; 5: 2*2, 1:1 coupler; 6: 2*2, 1:1 coupler; 7: light delay module; 8: 2*2, 1:1 coupler; 9: light delay module; 10: 1*2, 1:1 coupler.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

(2) The high-repetition-rate pulsed laser modulator provided by the present invention will be described as below in details in connection with the accompanying drawings by specific embodiments.

(3) As shown in FIG. 1, the high-repetition-rate pulsed, laser modulator provided by the present invention includes two 1*2, 1:1 couplers (1 and 10), N 2*2, 1:1 couplers (3, 5, 6, 8 and so on), and N light delay modules (2, 4, 7, 9 and so on), wherein one beam of pulsed laser whereof repetition rate is f can be divided into two beams with the same light intensity by a 1*2, 1:1 coupler 1; one beam of light passes through a fiber having a fiber length difference l compared with another, and a light delay module 2 used for modifying the fiber length difference l, then the two beams of light are coupled together into a 2*2, 1:1 coupler 3, the repetition rate of the output light now is 2f, In the same way, one beam of pulsed laser after 2*2, 1:1 coupler 3, passes through a fiber length difference l and a light delay module 4, and then the two beams of light are coupled together into a 2*2, 1:1 coupler 5, the repetition rate of the output light is 4f, After N 2*2, 1:1 couplers, and so on, the repetition rate of the output light is 2.sup.Nf, and then the two beams of light with the same light intensity are coupled together into a 1*2, 1:1 coupler 10, the repetition rate of the final output light is 2.sup.(N+2)f.

(4) The present invention described above just includes 3 kinds of devices: a 1*2, 1:1 coupler, a light delay module and a 2*2, 1:1 coupler, so it has simple devices, a compact structure and novel combination.