CN221353388U

CN221353388U - Laser frequency stabilizing circuit

Info

Publication number: CN221353388U
Application number: CN202322966421.7U
Authority: CN
Inventors: 肖勇
Original assignee: Zhongke Kuyuan Technology Wuhan Co ltd
Current assignee: Zhongke Kuyuan Technology Wuhan Co ltd
Priority date: 2023-11-01
Filing date: 2023-11-01
Publication date: 2024-07-16
Anticipated expiration: 2033-11-01

Abstract

The utility model relates to the technical field of atomic gravimeters, in particular to a laser frequency stabilization circuit, which comprises: a photodiode and a filter module for receiving a first electrical signal transmitted by the photodiode; the photodiode is used for receiving an optical signal and converting the optical signal into the first electric signal; the filter module comprises a plurality of filtering units which are connected in sequence, and the filtering units are used for receiving the first electric signals, filtering out signals except for modulation signals in the first electric signals and transmitting the modulation signals to a laser. The filtering unit in the filter module filters other interference signals from the photodiode, reduces noise and interference influence, and meets the requirement of laser frequency stabilization.

Description

Laser frequency stabilizing circuit

Technical Field

The utility model relates to the technical field of atomic gravimeters, in particular to a laser frequency stabilizing circuit.

Background

In atomic gravimeters, a laser with stable frequency is required, a frequency standard laser is generally used to give a light source, and in order to avoid frequency drift caused by temperature drift, a frequency locked related circuit is also used.

At present, the frequency stabilization locking of the laser is realized through a closed feedback loop, a photodiode transmits signals to the laser, a good locking signal can be obtained and the laser can be used as an independent module, but in the prior scheme, the photodiode obtains an electric signal by detecting an optical signal, the optical signal is modulated by a radio frequency signal, and the radio frequency signal can cause signal crosstalk through ground conduction and space radiation, so that the electric signal transmitted from the photodiode can contain a plurality of redundant other interference signals, the laser is easily interfered by the interference signals, and the frequency-standard laser cannot output frequency-standard laser according to the received electric signal.

In view of this, overcoming the drawbacks of the prior art is a problem to be solved in the art.

Disclosure of utility model

The utility model aims to solve the technical problems that: how to cancel the interference signal in the electrical signal from the photodiode.

The utility model adopts the following technical scheme:

the utility model provides a laser frequency stabilization circuit, which comprises: a photodiode for receiving an optical signal and converting the optical signal into a first electrical signal, and a filter module for receiving the first electrical signal transmitted by the photodiode;

The filter module comprises a plurality of filtering units which are connected in sequence, and the filtering units are used for receiving the first electric signals, filtering out signals except for modulation signals in the first electric signals and transmitting the modulation signals to a laser.

Preferably, the laser frequency stabilization circuit further comprises a feeder module, and the feeder module is connected with the photodiode;

the power feeder module comprises a first power supply, a first inductor, a first capacitor and a second capacitor which are sequentially connected in series, and the photodiode is connected between the first inductor and the first capacitor and is used for supplying power to the photodiode;

The feeder module further comprises a third capacitor, one end of the third capacitor is connected between the first power supply and the first inductor, and the other end of the third capacitor is grounded;

When the first power supply is positive, the cathode of the photodiode is connected between the first inductor and the first capacitor;

When the first power supply is negative, the anode of the photodiode is connected between the first inductor and the first capacitor.

Preferably, the filter module comprises a first filter unit, wherein the first filter unit comprises a second inductor, a fourth capacitor, a fifth capacitor and a sixth capacitor, and the fourth capacitor is connected in parallel with two ends of the second inductor;

One end of the second inductor is connected with the photodiode, and one end of the second inductor is also connected with one end of the fifth capacitor;

The other end of the second inductor is connected with one end of the sixth capacitor, and the other end of the fifth capacitor and the other end of the sixth capacitor are grounded.

Preferably, the filter module comprises a second filter unit, the second filter unit comprises a third inductor, a seventh capacitor and an eighth capacitor, one end of the third inductor is connected with the other end of the second inductor, and the seventh capacitor is connected in parallel with two ends of the third inductor;

The other end of the third inductor is connected with one end of the eighth capacitor, and the other end of the eighth capacitor is grounded.

Preferably, the filter module comprises a third filter unit, the third filter unit comprises a fourth inductor, a ninth capacitor and a tenth capacitor, one end of the fourth inductor is connected with the other end of the third inductor, and the ninth capacitor is connected in parallel with two ends of the fourth inductor;

The other end of the fourth inductor is connected with one end of the tenth capacitor, and the other end of the tenth capacitor is grounded.

Preferably, the filter module further includes a fourth filter unit, where the fourth filter unit includes a fifth inductor, an eleventh capacitor, and a twelfth capacitor, one end of the fifth inductor is connected to the other end of the fourth inductor, and the eleventh capacitor is connected in parallel to two ends of the second inductor;

The other end of the fifth inductor is connected with one end of the twelfth capacitor, and the other end of the twelfth capacitor is grounded.

Preferably, the laser frequency stabilization circuit further comprises an amplifier module, wherein the amplifier module is used for receiving the modulation signal transmitted by the filter module;

The amplifier module comprises a first amplifying chip and a second amplifying chip which are sequentially connected, and the amplifier module is used for sequentially amplifying the modulation signals through the first amplifying chip and the second amplifying chip and then transmitting the amplified signals to the laser.

Preferably, the amplifier module further comprises a fifth filtering unit, and the fifth filtering unit is connected with the first amplifying chip;

The fifth filter comprises a sixth inductor, a thirteenth capacitor and a fourteenth capacitor, one end of the fourteenth capacitor is connected with the filter module, and the other end of the fourteenth capacitor is connected with a radio frequency input pin of the first amplifying chip;

one end of the sixth inductor is connected with one end of the fourteenth capacitor, one end of the thirteenth capacitor is connected with one end of the fourteenth capacitor, and the other end of the sixth inductor and the other end of the thirteenth capacitor are grounded.

Preferably, the amplifier module further comprises a high-pass network unit, the high-pass network unit comprises a seventh inductor, an eighth inductor, a fifteenth capacitor and a ninth inductor, and the high-pass network unit is connected between the first amplifying chip and the second amplifying chip;

One end of the seventh inductor is connected with one end of the eighth inductor, and a radio frequency output pin of the first amplifying chip is connected between the seventh inductor and the eighth inductor;

The other end of the eighth inductor is connected with one end of the fifteenth capacitor, the other end of the fifteenth capacitor is connected with one end of the ninth inductor, and a radio frequency input pin of the second amplifying chip is connected between the fifteenth capacitor and the ninth inductor;

The other end of the seventh inductor and the other end of the ninth inductor are grounded.

Preferably, the amplifier module further comprises a pi-type filter, and the pi-type filter is connected with the second amplifying chip;

The pi-type filter comprises a sixteenth capacitor, a seventeenth capacitor and a tenth inductor, one end of the sixteenth capacitor is connected with the radio frequency output pin of the second amplifying chip, the other end of the sixteenth capacitor is connected with one end of the seventeenth capacitor, and the other end of the seventeenth capacitor is connected with the laser;

one end of the tenth inductor is connected between the sixteenth capacitor and the seventeenth capacitor, and the other end of the tenth inductor is grounded.

Compared with the prior art, the utility model has the beneficial effects that:

The laser frequency stabilization circuit provided by the utility model comprises a photodiode and a filter module, wherein the filter module is used for receiving a first electric signal transmitted by the photodiode; the photodiode is used for receiving the detected optical signal and converting the optical signal into the first electric signal; the filter module comprises a plurality of filtering units which are connected in sequence, and the filtering units are used for receiving the first electric signals, filtering out signals except for modulation signals in the first electric signals and transmitting the modulation signals to a laser. The filtering unit in the filter module filters other interference signals from the photodiode, reduces noise and interference influence, and meets the requirement of laser frequency stabilization.

Drawings

In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a laser frequency stabilization circuit according to an embodiment of the present utility model;

fig. 2 is a schematic diagram of a second structure of a laser frequency stabilization circuit according to an embodiment of the present utility model;

fig. 3 is a schematic diagram of a third structure of a laser frequency stabilization circuit according to an embodiment of the present utility model;

Fig. 4 is a schematic structural diagram of a feeder module of a laser frequency stabilization circuit according to an embodiment of the present utility model;

Fig. 5 is a schematic structural diagram of a filter module of a laser frequency stabilization circuit according to an embodiment of the present utility model;

Fig. 6 is a schematic diagram of a specific structure of a filter module of a laser frequency stabilization circuit according to an embodiment of the present utility model;

Fig. 7 is a schematic structural diagram of an amplifier module of a laser frequency stabilization circuit according to an embodiment of the present utility model;

Fig. 8 is a schematic diagram of a specific structure of an amplifier module of a laser frequency stabilization circuit according to an embodiment of the present utility model;

Fig. 9 is a schematic diagram of a pin structure of an amplifying chip of a laser frequency stabilizing circuit according to an embodiment of the present utility model;

Fig. 10 is a schematic diagram of a specific structure of a laser frequency stabilization circuit according to an embodiment of the present utility model;

Fig. 11 is a schematic diagram of a fourth structure of a laser frequency stabilization circuit according to an embodiment of the present utility model;

Fig. 12 is a flow chart of a frequency stabilization method of a laser frequency stabilization circuit provided by an embodiment of the utility model.

Detailed Description

The present utility model will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present utility model more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the utility model.

The terms "first," "second," and the like herein are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first", "a second", etc. may explicitly or implicitly include one or more such feature. In the description of the present utility model, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the present utility model, unless explicitly specified and limited otherwise, the term "connected" is to be construed broadly, and for example, "connected" may be either fixedly connected, detachably connected, or integrally formed; can be directly connected or indirectly connected through an intermediate medium. Furthermore, the term "coupled" may be a means of electrical connection for achieving signal transmission.

In addition, the technical features of the embodiments of the present utility model described below may be combined with each other as long as they do not collide with each other.

Example 1

An embodiment of the present utility model provides a laser frequency stabilization circuit, as shown in fig. 1, including: a photodiode and a filter module, the photodiode to receive an optical signal and to convert the optical signal into a first electrical signal; the filter module is used for receiving the first electric signal transmitted by the photodiode; the filter module comprises a plurality of filtering units which are connected in sequence, and the filtering units are used for receiving the first electric signals, filtering out signals except for modulation signals in the first electric signals and transmitting the modulation signals to a laser.

Wherein the photodiode is a device for converting light energy into electrical energy, and the first electrical signal is generated when an optical signal is irradiated onto the photodiode; as shown in fig. 2, an Electro-optical Modulator (EOM) may be further disposed at the front end of the photodiode, and the EOM module is a device capable of modulating an optical signal by changing an electric field, for receiving a radio frequency signal having phase coherence, modulating a phase, amplitude or frequency of the optical signal by changing the electric field of the EOM module, and transmitting the optical signal to the photodiode.

In a preferred embodiment, as shown in fig. 3 and 4, the laser frequency stabilization circuit further comprises a feeder module, which is connected to the photodiode; the power feeder module comprises a first power supply VCC1, a first inductor L1, a first capacitor C1 and a second capacitor C2 which are sequentially connected in series, and the photodiode is connected between the first inductor L1 and the first capacitor C1 and is used for supplying power to the photodiode; the feeder module further comprises a third capacitor C3, one end of the third capacitor C3 is connected between the first power supply VCC1 and the first inductor L1, and the other end of the third capacitor C3 is grounded; when the first power supply VCC1 is positive, the cathode of the photodiode is connected between the first inductance L1 and the first capacitance C1; when the first power VCC1 is negative, the anode of the photodiode is connected between the first inductance L1 and the first capacitance C1.

The other end of the second capacitor C2 is also connected with the filter module.

The first power supply VCC1 is a linear power supply of-12V to-5V or +12V to +5V, the first power supply VCC1 provides power supply voltage, and the first inductor L1 and the first capacitor C1 are connected in series to form an LC oscillating circuit. The photodiode is connected between the first inductor L1 and the first capacitor C1 for powering the photodiode. When the photodiode receives an optical signal, the oscillation frequency of the LC tank is changed.

The filtering unit in the filtering module is used for receiving the first electric signal and filtering stray signals except for the modulation signals in the first electric signal. The function of the filter module is to remove interference from non-modulated signals and to retain the modulated signals, wherein the specific structure of the filter module will be described below.

Next, a specific description will be given of the structure of the filter module, in a preferred embodiment, as shown in fig. 5, the filter module includes a first filtering unit, a second filtering unit, a third filtering unit, and a fourth filtering unit, where, as shown in fig. 6, the first filtering unit includes a second inductor L2, a fourth capacitor C4, a fifth capacitor C5, and a sixth capacitor C6, and the fourth capacitor C4 is connected in parallel to two ends of the second inductor L2; one end of the second inductor L2 is connected with the photodiode, and one end of the second inductor L2 is also connected with one end of the fifth capacitor C5; the other end of the second inductor L2 is connected to one end of the sixth capacitor C6, and both the other end of the fifth capacitor C5 and the other end of the sixth capacitor C6 are grounded.

The second filtering unit comprises a third inductor L3, a seventh capacitor C7 and an eighth capacitor C8, one end of the third inductor L3 is connected with the other end of the second inductor L2, and the seventh capacitor C7 is connected in parallel with two ends of the third inductor L3; the other end of the third inductor L3 is connected to one end of the eighth capacitor C8, and the other end of the eighth capacitor C8 is grounded.

The third filtering unit comprises a fourth inductor L4, a ninth capacitor C9 and a tenth capacitor C10, one end of the fourth inductor L4 is connected with the other end of the third inductor L3, and the ninth capacitor C9 is connected in parallel with two ends of the fourth inductor L4; the other end of the fourth inductor L4 is connected to one end of the tenth capacitor C10, and the other end of the tenth capacitor C10 is grounded.

The fourth filtering unit comprises a fifth inductor L5, an eleventh capacitor C11 and a twelfth capacitor C12, one end of the fifth inductor L5 is connected with the other end of the fourth inductor L4, and the eleventh capacitor C11 is connected in parallel with two ends of the second inductor L2; the other end of the fifth inductor L5 is connected to one end of the twelfth capacitor C12, and the other end of the twelfth capacitor C12 is grounded.

The filtering units are used for filtering and frequency selecting the first electric signal through serial-parallel combination of inductance and capacitance, removing interference of non-modulation signals and retaining modulation signals, wherein the filtering and the frequency selection are realized by the self properties of the inductance and the capacitance in the filtering units, namely, the inductance value and the capacitance value are determined. For example, taking a modulation frequency of 6.25MHz as an example, when the capacitance values of the fourth capacitor C4, the seventh capacitor C7, the ninth capacitor C9 and the eleventh capacitor C11 are all 10pF, the fifth capacitor C5, the sixth capacitor C6, the eighth capacitor C8, the tenth capacitor C10 and the twelfth capacitor C12 are respectively 820pF, 8nF, 1nF, 470pF and 100pF, and the second inductance L2, the third inductance L3, the fourth inductance L4 and the fifth inductance L5 are respectively 30nH, 27nH, 47nH and 30nH, the filter module can effectively suppress the signal above 30MHz in the first electrical signal, so as to reduce noise and interference effects.

In an actual application scenario, the corresponding capacitance or inductance value may be set according to the filtering requirement, which is not limited herein.

In a preferred embodiment, referring to fig. 3 and 7, the laser frequency stabilizing circuit further includes an amplifier module, where the amplifier module includes a fifth filtering unit, a first amplifying chip U1, a high-pass network unit, a second amplifying chip U2, and a pi-type filter, and the amplifier module is configured to receive the modulated signal transmitted by the filter module, and the function of the amplifier module is to amplify the modulated signal to increase the amplitude of the signal. The amplifier module comprises a first amplifying chip U1 and a second amplifying chip U2 which are sequentially connected, and the amplifier module is used for sequentially amplifying the modulation signals through the first amplifying chip U1 and the second amplifying chip U2 and then transmitting the amplified signals to the laser. The first amplifying chip U1 performs primary amplification on the modulation signal, and then transmits the modulation signal to the second amplifying chip U2 for further amplification. Finally, the amplified modulated signal is transmitted to a laser. The laser is a device capable of generating laser beams, and converts a modulation signal into a laser signal to realize stable frequency output of laser. Next, the structure of the amplifier module will be described.

In a preferred embodiment, referring to fig. 8, the fifth filtering unit is connected to the first amplifying chip U1; the fifth filter comprises a sixth inductor L6, a thirteenth capacitor C13 and a fourteenth capacitor C14, one end of the fourteenth capacitor C14 is connected with the filter module, and the other end of the fourteenth capacitor C14 is connected with a radio frequency input pin of the first amplifying chip U1; one end of the sixth inductor is connected with one end of the fourteenth capacitor, one end of the thirteenth capacitor is connected with one end of the fourteenth capacitor, and the other end of the sixth inductor and the other end of the thirteenth capacitor are grounded.

The fifth filtering unit is configured to couple the modulated signal transmitted from the filter module to the rf input pin of the first amplifying chip U1 through the fourteenth capacitor C14 after filtering the modulated signal through the sixth inductor L6 and the thirteenth capacitor C13.

Referring to fig. 8, the high-pass network unit includes a seventh inductor L7, an eighth inductor L8, a fifteenth capacitor C15, and a ninth inductor L9, and is connected between the first amplifying chip U1 and the second amplifying chip U2; one end of the seventh inductor L7 is connected with one end of the eighth inductor L8, and the radio frequency output pin of the first amplifying chip U1 is connected between the seventh inductor L7 and the eighth inductor L8; the other end of the eighth inductor L8 is connected with one end of the fifteenth capacitor C15, the other end of the fifteenth capacitor C15 is connected with one end of the ninth inductor L9, and the radio frequency input pin of the second amplifying chip U2 is connected between the fifteenth capacitor C15 and the ninth inductor L9; the other end of the seventh inductor L7 is grounded, and the other end of the ninth inductor L9 is grounded.

The high-pass network unit is used for suppressing low-frequency direct current noise components in the signal amplified by the first amplifying chip U1 so as to reduce the amplifying influence on the second amplifying chip U2, meanwhile, the combination of the series inductance and the capacitance of the high-pass network unit forms a high-pass filter which allows high-frequency signals to pass through and suppresses low-frequency signals, and the high-pass network unit is arranged between the first amplifying chip U1 and the second amplifying chip U2 so as to further regulate and filter the frequency of the signals and further optimize the frequency characteristics of the signals.

Referring to fig. 8, the pi-type filter is connected to the second amplifying chip; the pi-type filter comprises a sixteenth capacitor C16, a seventeenth capacitor C17 and a tenth inductor L10, wherein one end of the sixteenth capacitor C16 is connected with a radio frequency output pin of the second amplifying chip U2, the other end of the sixteenth capacitor C16 is connected with one end of the seventeenth capacitor C17, and the other end of the seventeenth capacitor C17 is connected with the laser; one end of the tenth inductor L10 is connected between the sixteenth capacitor C16 and the seventeenth capacitor C17, and the other end of the tenth inductor L10 is grounded.

The pi filter may act to further filter and adjust the frequency characteristics of the signal. By adjusting the parameters of the sixteenth capacitor C16, seventeenth capacitor C17 and tenth inductor L10, filtering and attenuation of signals of a specific frequency range can be achieved. Such a connection helps to further optimize the frequency response characteristics of the system and ensures that the laser receives a clean filtered signal. Meanwhile, stability and reliability of the circuit are guaranteed through the design of grounding. In which the filtering technique is known and not described too much in this embodiment.

In an alternative embodiment, the second power VCC2 may be a 12V linear power supply, and specific models of the first amplifying chip U1 and the second amplifying chip U2 may be BGA2869, and specific signal amplifying functions of the first amplifying chip U1 and the second amplifying chip U2 are not described in the present embodiment.

As shown in fig. 9, the power supply pins (i.e., 1 pin VCC) of the first amplifying chip U1 and the second amplifying chip U2 are connected with a second power supply VCC2, and the first ground pin (i.e., 4 pin GND 1), the second ground pin (i.e., 2 pin GND 2) and the third ground pin (i.e., 5 pin GND 2) of the first amplifying chip U1 and the second amplifying chip U2 are grounded. Rf_in (i.e., 6 pins) is the radio frequency input pin and rf_out (i.e., 3 pins) is the radio frequency output pin.

The specific connection relationship among the photodiode, the feeder module, the filter module and the amplifier module is shown in fig. 10. The specific structures of the feeder module, the filter module and the amplifier module are not described herein.

Example 2

In the laser stabilizing circuit proposed in embodiment 1, as shown in fig. 11, a mixer and a digital laser stabilizing module are further connected behind the amplifier module. The mixer is used to mix together signals of different frequencies, resulting in a new frequency combination. The digital laser frequency stabilization module is used for stabilizing the frequency of laser so as to ensure the stability and accuracy of signals.

Yet another reason for the amplifier module being used to amplify the modulated signal is that the mixer is not able to detect due to the smaller modulated signal.

The mixer is typically composed of a plurality of inputs and an output. The mixer is used for mixing the signal from the amplifier module with other frequency signals to generate a new frequency combination. The digital laser frequency stabilization module is a module for controlling and stabilizing the frequency output of the laser. The digital laser frequency stabilization module typically includes a digital control circuit and a feedback mechanism that can precisely adjust the frequency of the laser as needed and maintain it within a stable range. The mixer and the digital laser frequency stabilization module are connected behind the amplifier module, so that the signal can be further processed, the functions of frequency conversion, frequency stabilization and the like are realized, the requirements of different applications can be met, and stable and accurate signal output is provided.

The specific structure and the working principle of the mixer and the digital laser frequency stabilization module are all existing, and are not described too much in the embodiment.

Other structures of the laser frequency stabilization circuit are described in embodiment 1, and are not described in detail in this embodiment.

Example 3

In embodiment 1, a laser frequency stabilization circuit is provided, and in this embodiment, a frequency stabilization method is provided, which is applicable to the laser frequency stabilization circuit described in embodiment 1, as shown in fig. 12, and includes:

Step 101: the feeder module powers the photodiode, coupling a first electrical signal from the photodiode to the filter module.

Step 102: the filtering unit receives the first electric signal, filters out signals except for a modulation signal in the first electric signal, and transmits the modulation signal to the amplifier module.

Step 103: the amplifier module sequentially amplifies the modulation signals through the first amplifying chip U1 and the second amplifying chip U2 and transmits the amplified signals to the laser. The laser outputs laser with stable frequency according to the amplified modulation signal.

The specific structure of the laser frequency stabilizing circuit and the specific operation manner of each module thereof refer to embodiment 1, and are not described in detail in this embodiment.

The foregoing description of the preferred embodiments of the utility model is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the utility model.

Claims

1. A laser frequency stabilization circuit, comprising: a photodiode for receiving an optical signal and converting the optical signal into a first electrical signal, and a filter module for receiving the first electrical signal transmitted by the photodiode;

2. The laser frequency stabilization circuit of claim 1 further comprising a feeder module connected to the photodiode;

3. The laser frequency stabilization circuit of claim 1 wherein the filter module comprises a first filter unit comprising a second inductor, a fourth capacitor, a fifth capacitor and a sixth capacitor, the fourth capacitor being connected in parallel across the second inductor;

4. The laser frequency stabilization circuit of claim 3 wherein the filter module comprises a second filter unit, the second filter unit comprising a third inductor, a seventh capacitor and an eighth capacitor, one end of the third inductor being connected with the other end of the second inductor, the seventh capacitor being connected in parallel with the two ends of the third inductor;

5. The laser frequency stabilization circuit of claim 4 wherein the filter module comprises a third filter unit comprising a fourth inductor, a ninth capacitor and a tenth capacitor, wherein one end of the fourth inductor is connected with the other end of the third inductor, and the ninth capacitor is connected in parallel with two ends of the fourth inductor;

6. The laser frequency stabilization circuit of claim 5 wherein the filter module further comprises a fourth filter unit, the fourth filter unit comprising a fifth inductor, an eleventh capacitor and a twelfth capacitor, one end of the fifth inductor being connected to the other end of the fourth inductor, the eleventh capacitor being connected in parallel across the second inductor;

7. The laser frequency stabilization circuit of claim 1 further comprising an amplifier module for receiving the modulated signal transmitted by the filter module;

8. The laser frequency stabilization circuit of claim 7 wherein the amplifier module further comprises a fifth filter unit, the fifth filter unit being connected to the first amplification chip;

9. The laser frequency stabilization circuit of claim 7 wherein the amplifier module further comprises a high pass network element comprising a seventh inductance, an eighth inductance, a fifteenth capacitance, and a ninth inductance, the high pass network element being connected between the first and second amplification chips;

10. The laser frequency stabilization circuit of claim 7 wherein the amplifier module further comprises a pi filter, the pi filter being connected to the second amplification chip;