CN205429416U - Laser instrument with high stability - Google Patents

Abstract

The utility model discloses a laser instrument with high stability belongs to laser instrument technical field. The laser instrument includes: laser pipe, piezo electric crystal driver, branch slide, photoswitch, resonant cavity, synchronous detection unit, low -frequency modulation ware, interferometer, data processing unit and temperature compensating unit, divide the slide setting to be in in the laser output light path of laser pipe, just divide the slide branch the laser that the laser pipe produced obtains two light path branches, the photoswitch the resonant cavity with the synchronous detection unit sets gradually in the light path branch in two light path branches, the interferometer sets up in another light path branch in two light path branches, the low -frequency modulation ware simultaneously with the photoswitch and synchronous detection unit electricity is connected, the data processing unit with the interferometer electricity is connected, the piezo electric crystal driver simultaneously with the synchronous detection unit the data processing unit and temperature compensating unit electricity is connected.

Description

Laser with high stability

technical field

The utility model relates to the technical field of lasers, in particular to a laser with high stability.

Background technique

Semiconductor laser is a light source device with many advantages, such as small size, simple structure, good monochromaticity, good coherence, low working power supply voltage, etc. play an increasingly important role. Especially in basic physics research such as quantum physics, semiconductor lasers have played an indispensable and important role.

However, in the field of quantum physics, the frequency stability of the semiconductor laser output signal is very high. In order to ensure the frequency stability of the semiconductor laser output signal, the existing technology usually improves the frequency stability of the semiconductor laser by controlling the working conditions of the semiconductor laser. Such as controlling the operating temperature of semiconductor lasers.

However, even if the above-mentioned working conditions of the semiconductor laser are well controlled, the frequency stability of the output signal of the semiconductor laser is still not ideal, and it cannot meet the application requirements in high-end experiments, scientific research and other fields.

Utility model content

In order to solve the problems in the prior art, the embodiment of the utility model provides a laser with high stability. Described technical scheme is as follows:

The embodiment of the utility model provides a laser with high stability. The laser includes: a laser tube, a piezoelectric crystal driver, a beam splitter, an optical switch, a resonant cavity, a synchronous detection unit, a low-frequency modulator, an interferometer, a data processing unit and temperature compensation unit;

The beam splitter is arranged on the laser output optical path of the laser tube, and the laser beam generated by the laser tube is divided into two optical path branches by the beam splitter, and the optical switch, the resonant cavity and the synchronous detection unit sequentially arranged on one of the two optical path branches, and the interferometer is arranged on the other of the two optical path branches;

The low-frequency modulator is electrically connected to the optical switch and the synchronous detection unit at the same time, the data processing unit is electrically connected to the interferometer, and the piezoelectric crystal driver is simultaneously connected to the synchronous detection unit and the data processing unit. The processing unit is electrically connected to the temperature compensation unit.

In an implementation manner of the embodiment of the present utility model, the optical switch is an acousto-optic modulator.

In another implementation manner of the embodiment of the present utility model, the resonant cavity includes absorption bubbles filled with 87Rb atoms.

In another implementation manner of the embodiment of the present utility model, the temperature compensation unit includes:

A temperature conversion circuit, a differential amplifier circuit and a gain adjustment circuit, the differential amplifier circuit is electrically connected to the temperature conversion circuit and the gain adjustment circuit respectively.

In another implementation of the embodiment of the present utility model, the temperature conversion circuit includes a bridge, and the bridge includes a thermistor Rk, a resistor R0 and two resistors R, and the resistance value of the resistor R0 is the same as that of the The reference working temperature corresponds, and the temperature coefficient of the resistor R0 is the same as that of the thermistor Rk.

In another implementation of the embodiment of the present utility model, the differential amplifier circuit includes a first operational amplifier A1, a second operational amplifier A2, a third operational amplifier A3, two first resistors R1, and two second resistors R2 , the non-inverting input terminal of the first operational amplifier A1 is connected between the resistance R0 and the resistance R, and the inverting input terminal of the first operational amplifier A1 is connected with the output terminal of the first operational amplifier A1 , the non-inverting input terminal of the second operational amplifier A2 is connected between the thermistor Rk and the resistor R, the inverting input terminal of the second operational amplifier A2 is connected to the output of the second operational amplifier A2 The inverting input terminal of the third operational amplifier A3 is connected to the output terminal of the first operational amplifier A1 through one of the first resistors R1 in the two first resistors R1, and the third operational amplifier The non-inverting input terminal of A3 is connected with the output terminal of the second operational amplifier A2 through another first resistor R1 in the two first resistors R1, and the inverting input terminal of the third operational amplifier A3 is also connected through the One second resistor R2 of the two second resistors R2 is grounded, and the non-inverting input terminal of the third operational amplifier A3 is also connected to the third resistor R2 through the other second resistor R2 of the two second resistors R2. The output terminal of the operational amplifier A3 is connected, and the output terminal of the third operational amplifier A3 is also electrically connected with the piezoelectric crystal driver.

In another implementation of the embodiment of the present utility model, the gain adjustment circuit includes a third resistor R3, a variable resistor R4, and a fourth operational amplifier A4, and the third resistor R3 and the variable resistor R4 connected in series, the third resistor R3 and the variable resistor R4 are connected between the second resistor R2 connected to the non-inverting input terminal of the third operational amplifier A3 and the output terminal of the third operational amplifier A3 Between, the output terminal and the inverting input terminal of the fourth operational amplifier A4 are respectively connected to the two ends of the third resistor R3, and the non-inverting input terminal of the fourth operational amplifier A4 is grounded.

In another implementation manner of the embodiment of the present utility model, the piezoelectric crystal driver includes:

Three varactor diodes and an oscillator circuit, the input ends of the three varactor diodes are respectively connected to the synchronous detection unit, the synchronous detection unit and the output end of the temperature compensation unit, and the three varactors The output end of the diode is connected to the piezoelectric crystal driver at the same time.

In another implementation manner of the embodiment of the present utility model, the piezoelectric crystal driver further includes a constant temperature control circuit, and the constant temperature control circuit is electrically connected to the oscillator circuit.

In another implementation manner of the embodiment of the present utility model, the laser further includes an absorption chamber, and the absorption chamber is arranged on an optical path between the laser tube and the beam splitter.

The beneficial effects brought by the technical solution provided by the embodiment of the utility model are:

The laser output by the laser tube is divided into two paths through the beam splitter, one path generates the first deviation correction signal through the resonator and the synchronous detection unit, and the other path generates the second deviation correction signal through the interferometer and the data processing unit, and then passes through the temperature compensation unit according to the temperature. The third deviation correction signal, the above three deviation correction signals act on the laser tube through the piezoelectric crystal driver at the same time to ensure the frequency stability of the laser output signal, specifically: the first deviation correction signal is generated according to the atomic transition frequency in the resonant cavity, so The short-term stability of the laser output signal can be guaranteed. The second deviation correction signal is generated according to the optical frequency measurement of the interferometer, which can ensure the long-term stability of the laser output signal. The third deviation correction signal is generated according to the working environment temperature to ensure the laser output signal. Affected by ambient temperature.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some implementations of the present invention. For example, those of ordinary skill in the art can also obtain other drawings based on these drawings on the premise of not paying creative efforts.

Fig. 1 is a schematic structural diagram of a laser with high stability provided by an embodiment of the present invention;

Fig. 2 is a schematic structural diagram of a temperature compensation unit provided by an embodiment of the present invention;

Fig. 3 is a schematic structural diagram of a piezoelectric crystal driver provided by an embodiment of the present invention.

detailed description

In order to make the purpose, technical solutions and advantages of the present utility model clearer, the implementation of the present utility model will be further described in detail below in conjunction with the accompanying drawings.

Fig. 1 is a schematic structural diagram of a laser with high stability provided by the embodiment of the present invention. Referring to Fig. 1, the laser includes: a laser tube 10, a piezoelectric crystal driver 20, a beam splitter 30, an optical switch 40, and a resonant cavity 50 , synchronous detection unit 60, low frequency modulator 70, interferometer 80, data processing unit 90 and temperature compensation unit 100;

The beam splitter 30 is arranged on the laser output optical path of the laser tube 10, and the laser light generated by the laser tube 10 is divided into two optical path branches by the beam splitter 30, and the optical switch 40, the resonant cavity 50 and the synchronous detection unit 60 are arranged on the two optical path branches in turn. On one of the optical path branches, the interferometer 80 is arranged on the other optical path branch of the two optical path branches;

A low-frequency modulator 70, configured to generate a timing signal for controlling the optical switch 40 and a synchronization reference signal with the same frequency and phase as the timing signal;

The synchronous detection unit 60 is used to photoelectrically detect the optical signal passing through the resonant cavity 50 to obtain a photoelectric detection signal; use the photoelectric detection signal and the synchronous reference signal to perform synchronous phase detection, generate a first deviation correction signal, and output it to the piezoelectric crystal driver 20 ;

The data processing unit 90 is used to generate a second deviation correction signal according to the detection signal (DC level signal) generated by the interferometer 80, and output the second deviation correction signal to the piezoelectric crystal driver 20;

A temperature compensation unit 100, configured to generate a third deviation correction signal according to the working environment temperature, and output the third deviation correction signal to the piezoelectric crystal driver 20;

The piezoelectric crystal driver 20 is used to drive the laser tube 10 to work under the action of the first deviation correction signal, the second deviation correction signal and the third deviation correction signal.

The low-frequency modulator 70 is electrically connected to the optical switch 40 and the synchronous detection unit 60 at the same time, the data processing unit 90 is electrically connected to the interferometer 80, and the piezoelectric crystal driver 20 is electrically connected to the synchronous detection unit 60, the data processing unit 90 and the temperature compensation unit 100 at the same time. connect.

In this embodiment, the laser output from the laser tube is divided into two paths through the beam splitter, one path generates the first deviation correction signal through the resonator and the synchronous detection unit, and the other path generates the second deviation correction signal through the interferometer and the data processing unit, and then passes through the The temperature compensation unit generates the third deviation correction signal according to the temperature. The above three deviation correction signals act on the laser tube through the piezoelectric crystal driver at the same time to ensure the frequency stability of the laser output signal. Specifically: the first deviation correction signal is based on the The atomic transition frequency is generated, so the short-term stability of the laser output signal can be guaranteed. The second deviation correction signal is generated according to the optical frequency measurement of the interferometer, which can ensure the long-term stability of the laser output signal. The third deviation correction signal is generated according to the working environment temperature to ensure The laser output signal is not affected by the ambient temperature.

Optionally, the optical switch 40 is an acousto-optic modulator.

Optionally, resonant cavity 50 comprises an absorbing bubble filled with 87Rb atoms.

Fig. 2 is a schematic structural diagram of a temperature compensation unit 100 provided by an embodiment of the present invention. Referring to Fig. 2, the temperature compensation unit 100 includes:

A temperature conversion circuit 101, configured to convert the difference between the working environment temperature and the reference working temperature into a voltage difference;

The differential amplifier circuit 102 is used to differentially amplify the voltage difference to obtain a third deviation correction voltage;

The gain adjustment circuit 103 is configured to adjust the gain value of the differential amplifier circuit 102 .

The differential amplifier circuit 102 is electrically connected to the temperature conversion circuit 101 and the gain adjustment circuit 103 respectively.

Referring to Fig. 2 again, the temperature conversion circuit 101 includes an electric bridge, and the electric bridge includes a thermistor Rk, a resistor R0 and two resistors R, the resistance value of the resistor R0 corresponds to the reference working temperature, and the temperature coefficient of the resistor R0 is the same as that of the thermistor Rk is the same. The resistance value of resistor R0 represents the reference operating temperature. The thermistor Rk can be attached to the surface of the laser tube 10 to sense the working environment temperature of the laser tube 10 when it is working. Therefore, when the temperature of the working environment of the laser tube 10 does not change, the bridge in FIG. 2 is in balance. As the working environment temperature of the laser tube 10 increases (decreases), the resistance value of the thermistor Rk will decrease (increase), and there will be a voltage difference between the two ends of the bridge, which can be achieved through the differential amplifier circuit 102 and the gain adjustment circuit 103. Generate a correction voltage.

Referring to FIG. 2 again, the differential amplifier circuit 102 includes a first operational amplifier A1, a second operational amplifier A2, a third operational amplifier A3, two first resistors R1, two second resistors R2, and the non-inverting input of the first operational amplifier A1 terminal is connected between the resistor R0 and the resistor R, the inverting input terminal of the first operational amplifier A1 is connected with the output terminal of the first operational amplifier A1, and the non-inverting input terminal of the second operational amplifier A2 is connected between the thermistor Rk and the resistor R Between, the inverting input terminal of the second operational amplifier A2 is connected to the output terminal of the second operational amplifier A2, and the inverting input terminal of the third operational amplifier A3 is connected to the first resistor R1 through one of the two first resistors R1. The output end of an operational amplifier A1 is connected, the non-inverting input end of the third operational amplifier A3 is connected with the output end of the second operational amplifier A2 through another first resistor R1 in the two first resistors R1, the third operational amplifier A3 The inverting input terminal is also grounded through one of the second resistors R2 of the two second resistors R2, and the non-inverting input terminal of the third operational amplifier A3 is also connected to the third operational amplifier A3 through the other second resistor R2 of the two second resistors R2. The output terminal of the amplifier A3 is connected, and the output terminal of the third operational amplifier A3 is also electrically connected with the piezoelectric crystal driver 20 .

Referring to FIG. 2 again, the gain adjustment circuit 103 includes a third resistor R3, a variable resistor R4 and a fourth operational amplifier A4, the third resistor R3 and the variable resistor R4 are connected in series, and the third resistor R3 and the variable resistor R4 are connected Between the second resistor R2 connected to the non-inverting input terminal of the third operational amplifier A3 and the output terminal of the third operational amplifier A3, the output terminal and the inverting input terminal of the fourth operational amplifier A4 are respectively connected to the third resistor R3. Both ends, the non-inverting input terminal of the fourth operational amplifier A4 is grounded.

Fig. 3 is a schematic structural diagram of a piezoelectric crystal driver 20 provided by an embodiment of the present invention. Referring to Fig. 3, the piezoelectric crystal driver 20 includes:

Three varactor diodes (D1, D2 and D3) and an oscillator circuit 201, the input ends of the three varactor diodes are respectively connected to the synchronous detection unit 60, the synchronous detection unit 60 and the output end of the temperature compensation unit 100, and the three varactors The output end of the capacitor diode is connected to the piezoelectric crystal driver 20 at the same time.

Wherein, the varactor diode outputs different capacitance values according to different input voltages, thereby fine-tuning the output signal frequency value of the oscillator circuit.

Referring again to FIG. 3 , the piezoelectric crystal driver 20 further includes a constant temperature control circuit 202 , and the constant temperature control circuit 202 is electrically connected to the oscillator circuit 201 . Preferably, the constant temperature control circuit 202 can be realized by the temperature supplementing unit 100, and the specific implementation manner will not be repeated here.

Referring to Fig. 1 again, the laser also includes an absorption chamber 110, the absorption chamber 110 is arranged on the optical path between the laser tube 10 and the beam splitter 30, the absorption chamber 110 is used to select a laser signal of a set frequency from the laser output from the laser tube, To ensure the accuracy of subsequent processing.

Those of ordinary skill in the art can understand that all or part of the steps for implementing the above embodiments can be completed by hardware, and can also be completed by instructing related hardware through a program. The program can be stored in a computer-readable storage medium. The above-mentioned The storage medium mentioned may be a read-only memory, a magnetic disk or an optical disk, and the like.

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present utility model shall be included in this utility model. within the scope of protection of utility models.

Claims (10)

1. A laser with high stability, characterized in that the laser comprises: a laser tube, a piezoelectric crystal driver, a beam splitter, an optical switch, a resonant cavity, a synchronous detection unit, a low-frequency modulator, an interferometer, a data processing unit and temperature compensation unit; The beam splitter is arranged on the laser output optical path of the laser tube, and the laser beam generated by the laser tube is divided into two optical path branches by the beam splitter, and the optical switch, the resonant cavity and the synchronous detection unit sequentially arranged on one of the two optical path branches, and the interferometer is arranged on the other of the two optical path branches; The low-frequency modulator is electrically connected to the optical switch and the synchronous detection unit at the same time, the data processing unit is electrically connected to the interferometer, and the piezoelectric crystal driver is simultaneously connected to the synchronous detection unit and the data processing unit. The processing unit is electrically connected to the temperature compensation unit. 2. The laser according to claim 1, wherein the optical switch is an acousto-optic modulator. 3. The laser according to claim 1, wherein the resonant cavity comprises an absorbing bubble filled with ⁸⁷ Rb atoms. 4. The laser according to claim 1, wherein the temperature compensation unit comprises: A temperature conversion circuit, a differential amplifier circuit and a gain adjustment circuit, the differential amplifier circuit is electrically connected to the temperature conversion circuit and the gain adjustment circuit respectively. 5. laser according to claim 4, is characterized in that, described temperature conversion circuit comprises electric bridge, and described electric bridge comprises thermistor Rk, resistance R0 and two resistance R, and the resistance value of described resistance R0 and The reference working temperature corresponds, and the temperature coefficient of the resistor R0 is the same as that of the thermistor Rk. 6. The laser according to claim 5, wherein the differential amplifier circuit comprises a first operational amplifier A1, a second operational amplifier A2, a third operational amplifier A3, two first resistors R1, two second Resistor R2, the non-inverting input end of the first operational amplifier A1 is connected between the resistance R0 and the resistance R, the inverting input end of the first operational amplifier A1 is connected to the output of the first operational amplifier A1 terminal connection, the noninverting input terminal of the second operational amplifier A2 is connected between the thermistor Rk and the resistor R, the inverting input terminal of the second operational amplifier A2 is connected to the second operational amplifier A2 connected to the output terminal of the third operational amplifier A3, the inverting input terminal of the third operational amplifier A3 is connected to the output terminal of the first operational amplifier A1 through one of the first resistor R1 in the two first resistors R1, and the third operational amplifier A3 The non-inverting input terminal of the operational amplifier A3 is connected to the output terminal of the second operational amplifier A2 through another first resistor R1 in the two first resistors R1, and the inverting input terminal of the third operational amplifier A3 is also connected to the output terminal of the second operational amplifier A2. One of the second resistors R2 of the two second resistors R2 is grounded, and the non-inverting input terminal of the third operational amplifier A3 is also connected to the second resistor R2 of the two second resistors R2. The output terminal of the third operational amplifier A3 is connected, and the output terminal of the third operational amplifier A3 is also electrically connected with the piezoelectric crystal driver. 7. The laser according to claim 6, wherein the gain adjustment circuit comprises a third resistor R3, a variable resistor R4 and a fourth operational amplifier A4, the third resistor R3 and the variable resistor The resistor R4 is connected in series, the third resistor R3 and the variable resistor R4 are connected to the output of the second resistor R2 connected to the non-inverting input terminal of the third operational amplifier A3 and the third operational amplifier A3 Between terminals, the output terminal and the inverting input terminal of the fourth operational amplifier A4 are respectively connected to both ends of the third resistor R3, and the non-inverting input terminal of the fourth operational amplifier A4 is grounded. 8. The laser according to claim 1, wherein the piezoelectric crystal driver comprises: Three varactor diodes and an oscillator circuit, the input ends of the three varactor diodes are respectively connected to the synchronous detection unit, the synchronous detection unit and the output end of the temperature compensation unit, and the three varactors The output end of the diode is connected to the piezoelectric crystal driver at the same time. 9. The laser according to claim 8, wherein the piezoelectric crystal driver further comprises a constant temperature control circuit, the constant temperature control circuit is electrically connected to the oscillator circuit. 10 . The laser according to claim 1 , further comprising an absorption chamber, the absorption chamber being arranged on the optical path between the laser tube and the beam splitter. 11 .