SU1202476A1 - Device for stabilizing laser frequency - Google Patents

Description

The invention relates to the field of technical physics, and more specifically to quantum electronics, and can be used to create dual-frequency stabilized gas lasers used in precision machine engineering and for precision measurement of linear displacements.

The purpose of the invention is to increase the frequency stability of the radiation.

An increase in the frequency stability is achieved by eliminating periodic modulation and the treatment of the resulting effects in accordance with the derivative of their changes.

N3 O GO L.

FIG. 1 shows the functional scheme of the device; FIG. 2 shows the dependence of the frequency Cf of the beat signal from the photodetector output on the laser radiation frequency. The arrows indicate the direction of change in the laser radiation frequency during operation, where f is the beat signal frequency, fi and fa are two instantaneous frequencies, v is the laser radiation frequency, Vo is the average radiation frequency in the stabilization mode.

The device for frequency stabilization contains a laser 1 with a frequency control device, for example, a piezocorrector 2, a photodetector 3, a reversible counter 4, a buffer memory 5 with an output. The sign of the number 6, 7 and inverse 8 outputs, the master oscillator 9, the synchronizer 10c outputs the counting direction 11 and Reset 12, first switch 13, digital-to-analog converter (D / A converter) 14, adder 15, reference voltage source 16, inverter 17, second switch 18, counting trigger 19, power amplifier 20.

The device works as follows.

Laser 1 generates two-frequency radiation, the signal of the beat frequency of which is emitted by the photoreceiver 3. This signal has an extremum in dependence of the beat frequencies on the optical frequency v (Fig. 2). The voltage from the voltage source 16 and from the DAC 14, through the adder 15, switch 18, power amplifier 20 acts on the piezocorrector 2, which leads to a certain shift in the optical frequency V. The difference frequency f changes in accordance with the optical frequency V. A reversible counter 4, for a back and forth switching cycle, calculates the beat frequency fa and fi (Fig. 2), subtracting fi from fa. At the moment of the end of the counting cycle, the difference between the frequencies f2 fi is transferred to the buffer memory 5. information about the sign of the difference fa-f 1, which is output through the sign output 6,. And the information about the absolute value of the difference fa-fi is output through the direct 7 and inverse 8 outputs. The synchronization of the operation of the memory device 5, the reversible counter 4 and the transfer of information to the buffer memory 5 is provided by the master generator 9 and the synchronizer 10 whose signal from the output. The counting direction 11 controls the forward and reverse counting of the reversing

the counter 4, and the output signal Reset 12 controls the transfer of the value of fa - fi to the buffer memory 5 and simultaneously flushes the reversing counter 4

preparing it for a new measurement cycle. If the difference fa - fi has a negative sign, then this, in this case, indicates that the optical frequency v changes in the direction of the nominal frequency, i.e.

to an extremum depending on f (v) (Fig. 2). In this case, the switch 13 connects to the DAC 14 the inverting output 8 of the buffer memory 5, and the counting trigger 19 and the switch 18 remain in

the previous position, which ensures further movement of the optical frequency in the direction of the nominal value (Fig. 3). If the difference has a positive sign, then it indicates that

the optical frequency v changes in the opposite direction from the nominal value of Vo. In this case, the switch 13 connects to the D / C converter 14 direct output 7 of the buffer memory 5,

the counting flip-flop 19 is shifted to the opposite state and the switch 13 connects the output from the inverter 17 to the power amplifier 20 if the output of the adder 15 was connected before or connects the output of the adder 15 if the output of the inverter 17 was connected before. the optical frequency v towards the nominal VQ. The digital-to-analog converter 14 produces a signal that controls the rate of change of the optical frequency v. When the optical frequency approaches the optimal value of the VO, its rate of change decreases, which significantly reduces the natural frequency oscillations of the laser.

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Claims (1)

(54X57) A DEVICE FOR STABILIZING A LASER FREQUENCY, comprising a laser with a piezo corrector, a photodetector installed at the laser output, the output of which is connected to a reversible counter and a buffer memory in series, a synchronizer with a master oscillator, synchronizer outputs, the counter direction and the reset are connected to two counter inputs and are connected to two and a reset output with an input of a buffer storage device, as well as a digital-to-analog converter and a power amplifier connected to a piezoelectric corrector, characterized in that, in order to increase the stability of the radiation frequency, two switches are introduced into it, an adder with a reference voltage source, an inverter and a trigger, while the direct and inverse outputs of the buffer memory are connected through two inputs of the first switch to a digital-to-analog converter, the output of which connected to one of the inputs of the adder, the output of which is connected to the inverter and to one of the inputs of the second switch, the output of which is connected to the input of the power amplifier, and the control input is connected to Exit trigger control input of the first switch and the trigger input connected to the output "sign of the buffer memory, and the inverter output is connected to a second input of the second switch.