JPS6035588A - Frequency stabilized laser device - Google Patents

Abstract

PURPOSE:To exactly keep constant the resonator length of a laser resonator by a method wherein the positive and negative natures of the difference between a reference frequency and a photo beat frequency are discriminated, and then the electric signal increasing and decreasing according to the positive and negative natures of the frequency difference is added to the signal impressed on a blower driving motor. CONSTITUTION:The photo beat is detected by a detector 3 by passing the oscillated light of a laser oscillation tube 1 in a weak magnetic field through a polarizer 2 and then amplified by a wide band amplifying circuit 4, and the frequency is converted into a voltage by a frequency- voltage converter 5, resulting in obtaining the difference of a meta-reference frequency setter 8 between the meta-reference voltage by a differential amplifying circuit 9. On the other hand, the photo beat frequency is compared, in a comparator 6, with the frequency of a reference frequency generator (reference frequency setting section) 7, the converted into the electric signal slowly increasing and decreasing according to the frequency difference in a circuit 10 having the function of integration, after generating positive and negative voltages according to the negative and positive natures of the difference, and accordingly added to the signal passing through said section 8 by an adder 11. This signal which is slowly increasing and decreasing corrects the bias voltage. The corrected signal is applied to the motor M of the blower.

Description

[Detailed description of the invention]

The present invention relates to a device for stabilizing the oscillation frequency of a racer. When internal light in the earth's magnetic field or other magnetic field is passed through a polarizer, the optical heat becomes +1111, and as the frequency of the optical heat becomes constant, <J(& By controlling the mirror spacing, the oscillation station l
It is possible to control the interval of the J-mirror by setting the reciprocal number of ray→J- to 1;
I (I know that it is good to control the temperature of the tube, and for that purpose, the blower must be used to control the coolness of the air around the electrician. This is accomplished by a device inside the tube. However, the difference between the optical heat frequency and the desired set frequency is detected, and if the optical beat frequency is different from the set frequency, the electric current applied to the blower is adjusted so that the frequency difference disappears.
It is a matter of skill to adjust the value of E and control the distance between the vibrating mirrors, that is, the vibrator length, so that the beat frequency is constant. This direction V, if the temperature around the laser device flJI is constant, 1. 'l shows excellent performance. As the ambient temperature changes, the disadvantage is that the frequency changes. Since the adjustment is an ineffective f + J function, a constant bias air flow rate must always be given and adjustment around it will make fL equal.Therefore, the voltage applied to the blower's motor will decrease by 11 when the bias I is turned on. However, since there is a unique correspondence between the voltage and the heat frequency, it becomes difficult when the temperature changes.In other words, when the temperature changes, It takes 1 wind f1

[Or lose weight. Therefore, electric motor 0)1
cI1. The output frequency also changes, and the output frequency corresponding to ILH changes, and thus the oscillation frequency changes. The present invention provides a laser oscillation frequency control device that uses a blower as its main component, even if there is a change in the ambient temperature. 1if
This invention relates to a control system that does not cause a change in the E wave number, and the present invention makes it possible to realize a device that stabilizes the number of 14 cycles and is not affected by changes in the environment. 11'4 is an explanatory diagram of control jI: 7).
Detect I, convert the number of light heat cycles to electric H, and
Let X be the applied voltage when 1 (is applied to the electric motor of the blower).
The ζth high anno is the sum of 2 per month. Because of the light heat cycle, when a change occurs, the voltage y changes, and the light heat 1-
When the number of laps and Jk is set to 4+1+, the frequency is stabilized. However, the pressure X is determined by the extremely delicate balance between the heat generated by the racer discharge tube and the amount of cooling, so the surrounding temperature remains perfectly stable. When the temperature fluctuates, it changes slightly accordingly.At a certain temperature, the voltage When the bias voltage 2 is adjusted and set, stabilization starts, but if the bias voltage 2 is constant, when the temperature changes, in order to balance In addition, the optical beat frequency changes.The present invention prevents the optical beam 1 frequency and ultimately the laser oscillation frequency from changing even if the temperature changes.In other words, there is no sign of a change in the optical beat frequency from the set value. When , the value of bias electric moon 2 is gradually changed to suppress the change in the optical beat frequency, and when X changes, y does not change, only 2 changes, and temperature change 19. Figure 2 shows an embodiment of the present invention.The oscillation light of the laser beam tic+ in a weak magnetic field is passed through polarized light 2f2, and the optical beat is detected and detected in the detection interval 3. Increase it M approximately 4 and increase 11" frequency -', u 11: 14
The converter 5 converts the frequency to °C and increases the frequency by 1+. The standard '^1/frequency setting section is for setting hi including bias Z. The output beat frequency is compared with the frequency of the reference frequency generator (frequency setting section) by the comparison circuit (). Ratio Il + Q circuit fi f4 comparison
] Even if the Z of the frequency is shifted, I'/' (E is 11 of S, negative 1 corresponds to positive, negative 1tjl earth (1. Generated jl, or negative fj) Y( The i pressure is a long time constant.) b'J minute 1741 circuit or the counter snow accumulation 5J function in circuit 1 (), which increases and decreases slowly according to the frequency difference, is changed to 1, II and added in the pth circuit, Previous((
1h and 1 (Add 9 and f to No. 414 that passed through the frequency setting section. The slowly increasing and decreasing +, i'; is +iiJ notation, (1) Complement J[, of the value is 7f. Complement 11 :(j 'J is added to the electric motor M of the sending!la machine). Figure 2 shows another embodiment. In this example,
In electrical circuits, jf, quasi J, L 71! The frequency setting part is set to J, and the 11 bow is increased by 11 to 12 by the intensifier 12.16 In addition to the motive N1, the output of the circuit 10 is Lehner b
This is an example in which a part of the electric tube is burnt and the heater is driven to thermally heat the tube. Figures 3 and 3 show other embodiments. In the example of C, optical beat toy 1
After the frequency of ' is converted into voltage fr't ((
ξ reference frequency setting section and ) J quasi-frequency setting section. VH2 is a reference standard (corresponding to the indwelling wave number output from the frequency setting section, and is a bottom value that determines the voltage and bias λ-.The difference between the voltage of the bottom weight meter VR2 and the frequency-voltage converted voltage) is incremented by 4 and becomes one input of the operational term lJ5. Decide on main 1. Increase +
2i+13 is an intensifier I+ with infinite gain, and if the frequency-voltage converted voltage is even slightly distorted, rl. If it is low, it emits a constant electric current of +1, 41 (1), C is an integrating circuit with a long time constant, and it is a constant 11ffl11. The voltage is amplified by an intensifier 16 and inputted to the other input terminal of the arithmetic amplifier 15, and the voltage added by the arithmetic amplifier 15 is applied to the motor M.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating the principle, and FIG. 2 is an embodiment of the present invention. FIG. 4 is another embodiment. 1...Laser tube 2...Polarizer 3...Detector 5...-Frequency-voltage converter 6...-Comparison circuit 7-・JA quasi-station frequency setter --i'1! +)A 116 Frequency setting F1. '
4! ), + 2-11T & Ifl I item 1()-
...Circuit 11 that scales the integral function - Addition Z'11 circuit 1, (... profit? 1) Infinite amplifier" 4.15.1
Era・-・Direct increase 11J Ri4M-... Blower drive motor Phantom past 41 yen 1

Claims (1)

[Claims] By changing the wind Ul of the blower so that the optical heat frequency of the light emitted light is constant, two wastes caused by the earth's field and other weak magnetic fields can be improved.
A frequency stabilizing relay → that controls the temperature of tr tq is placed in one device, and flower 9! A reference standard for setting the frequency and the bias value of the blower drive motor.
(Standard standard 7i1 - Convert the difference between the set value set in the frequency setting section and the optical beat station wave number to 1a air signal) and apply it to the blower drive 1 [L motor by adding the bias standard (if). The application 4:,1''j is varied to keep the laser resonator length constant, and the positive or negative of the wave number and the optical beat frequency set by the reference frequency setting section 110 is determined. Then, a circuit having an integral function or the like is used to create electricity No. 411 that gradually increases or decreases in accordance with the colorimetry of the frequency difference, and the Gj No. 411 is applied to the blower drive motor h. A frequency-regulated racer device characterized in that the length of the carrier is maintained accurately constant by adding the laser beam to the laser beam and the length of the carrier is kept accurately constant.