CN102738694A

CN102738694A - Method for realizing laser frequency stabilization by utilizing Fabry-Perot (F-P) interferometer

Info

Publication number: CN102738694A
Application number: CN2012102115509A
Authority: CN
Inventors: 刘豪; 舒嵘; 胡以华; 葛明锋; 王亚南
Original assignee: Shanghai Institute of Technical Physics of CAS
Current assignee: Shanghai Institute of Technical Physics of CAS
Priority date: 2012-06-25
Filing date: 2012-06-25
Publication date: 2012-10-17

Abstract

The invention discloses a method for realizing laser frequency stabilization by utilizing a Fabry-Perot (F-P) interferometer. The method is characterized by comprising the following steps of: scanning laser to be stabilized by utilizing a confocal F-P interferometer which can perform cavity length scanning to acquire a scanning signal from a probe behind the F-P interferometer; acquiring frequency information of laser to be detected by analyzing time characteristics of the laser to be detected; and controlling the frequency by using a feedback loop. The method is simple, and the frequency of laser with the wavelength of the sub pm magnitude is easily stabilized.

Description

A kind of method of utilizing the F-P interferometer to realize laser frequency stabilization

Technical field

The present invention relates to a kind of laser steady frequency technology, be specifically related to the method that a kind of F-P of utilization interferometer is realized laser frequency stabilization, it is mainly used in the optical pickocff of optical wavelength type, Atmospheric Survey for example, tachometric survey.

Background technology

The stability of laser frequency has significance to laser acquisition technology such as laser radars, for example adopts Doppler's coherent wind laser radar of laser steady frequency technology, and its certainty of measurement can improve greatly.At present the method for laser frequency stabilization mainly contains following two kinds: utilize gas cell absorption line source as a reference, carry out frequency stabilization according to the intensity signal of laser after through gas cell; Utilize the narrow linewidth characteristic of F-P interferometer filter, carry out frequency stabilization according to the strength information of laser through the F-P interferometer.More than two kinds of methods to add a little modulation signal to laser, obtain frequency change information through the phase demodulation mode, and feed back to processor, thereby realize laser frequency stabilization.Its major defect is that the signal that obtains is a weak signal, extracts difficulty, receives The noise easily, and the small modulation of introducing also has certain influence to laser frequency itself.

Summary of the invention

In order to overcome the deficiency of prior art, the invention provides a kind of frequency-stabilizing method based on confocal cavity Fabry-Perot interferometer and time measurement, technical scheme is following:

This method realizes in order to lower device; Concrete like accompanying drawing 1, comprising: the confocal cavity F-P interferometer of the tunable laser of built-in piezoelectric ceramic, condenser lens, the long scan of band chamber, F-P interferometer controller, light signal receiving conditioning circuit, time measurement module, processor and piezoelectric actuator.Wherein, The laser that tunable laser is sent focuses on F-P interferometer inside through condenser lens; The F-P interferometer is by F-P interferometer controller drives, and the light signal receiving conditioning circuit receives the light signal through F-P, and the temporal information of time measurement module measuring light signal also feeds back to processor; Processor calculates back control piezoelectric actuator, and piezoelectric actuator drives the inner piezoelectric ceramic of tunable laser.

Implementation procedure of the present invention is shown in accompanying drawing 2: tunable laser output laser incides confocal cavity F-P interferometer through condenser lens; The F-P interferometer is driven by sawtooth signal and carries out the chamber long scan; The signal that detector receives amplifies; When the frequency change of laser, have the regular hour relation between signal that detector obtains and the F-P drive signal, this time quantum is measured; The temporal information that obtains is through processor processes and feed back to the piezoelectric ceramic that piezoelectric actuator drives tunable laser inside, thus the stabilized lasers frequency.

Accompanying drawing 3 is the important waveform of part, and the first via is for driving the sawtooth waveforms of F-P interferometer, and the second the tunnel is the sweep signal that light frequency obtains during for f1; Rising edge at each sawtooth waveforms; We can obtain 2 signal peaks, and this is because the sweep limits of F-P interferometer has surpassed a wavelength, during the integral multiple of chamber long scan to the optical maser wavelength of each F-P; Laser can almost completely pass through the F-P interferometer, other the time laser almost can not pass through the F-P interferometer.T1 is the time of F-P interferometer drive signal starting point to first peak value; T2 is an another one optical maser wavelength; The F-P interferometer drives the time of starting point to first peak value, and we can learn, when optical maser wavelength changes; The time corresponding measured value also can change, and this point is patent of the present invention and the maximum difference of other patent.

The invention has the beneficial effects as follows that the light signal that obtains is strong signal, so signal to noise ratio is much larger than conventional method; Utilize time measurement to replace traditional luminous intensity measurement,, therefore can realize the laser frequency stabilization effect of high stability, and this frequency stabilization mode can not make laser output stack one additional frequency because the relative accuracy of time measurement is higher than the precision of ionization meter far away.

Description of drawings

Fig. 1 utilizes the F-P interferometer to realize the structural representation of laser frequency stabiliz ation method.

Wherein: the confocal cavity F-P interferometer of tunable laser, condenser lens, the long scan of band chamber, F-P interferometer controller, light signal receiving conditioning circuit, time measurement module, processor and piezoelectric actuator.

Fig. 2 is the workflow diagram of system.

Fig. 3 directly concerns for different frequency place signal conditioning circuit output waveform and F-P interferometer sawtooth waveforms drive waveforms.

Claims

1. method of utilizing the F-P interferometer to realize laser frequency stabilization; It is characterized in that: tunable laser output laser incides confocal cavity F-P interferometer through condenser lens; The F-P interferometer is driven by sawtooth signal and carries out the chamber long scan, and the signal that detector receives amplifies, when the frequency change of laser; Have the regular hour relation between signal that detector obtains and the F-P drive signal; This time quantum is measured, and the temporal information that obtains is through processor processes and feed back to the piezoelectric ceramic that piezoelectric actuator drives tunable laser inside, thus the stabilized lasers frequency.