NOVEL 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: $.Math..Math.l=\left(\mathrm{kt}+\frac{t}{2}\right).Math.\frac{c}{n};$ 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.

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Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] 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

[0011] 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.

[0012] 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 2 f, 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 4 f, 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.

[0013] 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.