Alkali metal gas chamber, laser transmitter and gas chamber replacement method

Abstract

The present application discloses an alkali metal gas chamber, a laser emitter and a gas chamber replacement method, which solves the problem of waste heat accumulation in the gas chamber in the prior art. The alkali metal gas chamber comprises a carrier plate and a gas chamber. The carrier plate has a through hole for installing the gas chamber. The carrier plate drives the through hole to reciprocate from facing the light to leaving the light. The alkali metal laser uses the above-mentioned alkali metal gas chamber, and also comprises a light source, a heating device, a first resonant cavity mirror and a second resonant cavity mirror. The light source, the first resonant cavity mirror, a rotatable alkali metal gas chamber and the second resonant cavity mirror are sequentially installed on the light path. When the through hole is away from the light source, the disk surface of the carrier plate blocks the light source. The heating device maintains the temperature of the gas chamber. The alkali metal gas chamber of the present application realizes the alternating heat dissipation of the alkali metal vapor in the gas chamber. The damaged alkali metal vapor chamber can be replaced in time during use. The laser of the present application makes full use of the pump light energy, has a low cost, and is suitable for pulsed low-power output alkali metal lasers.

Description

Technical Field

[0001] The present application relates to the field of laser surgery, and in particular to an alkali metal gas chamber, a laser transmitter, and a gas chamber replacement method. Background Art

[0002] Achieving high-power laser output has always been the research focus in the field of laser technology. High-power and high-efficiency energy injection, high energy conversion efficiency, high beam quality and effective waste heat management are the key development directions of high-power lasers. Diode Pumped Alkali Vapor Laser (DPAL) uses semiconductor lasers as pump sources, which is the easiest way to achieve continuous and stable energy injection; alkali metals have high quantum efficiency, and can achieve efficient energy absorption by adding buffer gas to broaden the absorption spectrum; using alkali metal vapor as the gain medium can achieve effective waste heat management by rapid heat dissipation through flow; operating under closed conditions, without the use of hazardous chemicals, is safer and more convenient. With its unique advantages, the diode pumped alkali metal vapor laser has become a highly potential technical solution for achieving high-power laser output, and has great development potential and broad development prospects in the fields of laser energy transmission, optoelectronic countermeasures, laser processing and laser medical treatment in the future.

[0003] At present, the most commonly used gas chamber for low-power semiconductor-pumped alkali metal vapor lasers is a glass bubble filled with rubidium vapor and buffer gas or a closed metal cavity equipped with a window plate. The two sides of the gas chamber are wrapped by an aluminum shell with a heating plate installed. The gas chamber is set between two resonant cavity mirrors to form a resonant cavity. The semiconductor laser after line width narrowing and beam shaping is injected into the resonant cavity as pump light. The ground state particles of alkali metal atoms in the gas chamber absorb the pump light and are excited to 2P3 / 2 and then quickly relax to the 2P1 / 2 energy level. The number of upper energy level particles on the excited rays can be rapidly accumulated to achieve particle number inversion. After self-excited oscillation, the stimulated radiation amplification output of the alkali metal laser is finally realized.

[0004] In the case of continuous pump light injection, a large amount of waste heat can easily accumulate in the closed air chamber, causing the air chamber temperature to rise and the air chamber temperature control system to be unable to control the air chamber temperature in time to keep it stable. If the air chamber is filled with alkane buffer gas, such gas will react with alkali metal atoms at a higher temperature to produce alkali metal hydrates or carbon particles to contaminate the light-transmitting surface of the glass bulb or the window of the closed metal air chamber, thereby damaging the optical system and causing the laser output power to drop or even fail to output alkali metal lasers. Frequently damaged and contaminated glass bulbs or windows will increase the experimental cost, and replacing glass bulbs or windows will also delay the experimental process. In order to extend the service life of the glass bulb, the experimenter will use a chopper to chop the pump light, changing the continuous pump light injection into a pulsed pump light injection. The chopper refers to an electronically controlled fan-type impeller that modulates (chops) the continuous light into a periodic intermittent light of a certain frequency at a certain speed, and the cutoff time is equal to the light transmission time, changing the constant light source into a variable "square wave" light source. However, this method also has some problems: if the size of the chopper does not match the semiconductor pump light, it is easy to block part of the pump light, resulting in a decrease in the pump light injection efficiency; the slight shaking of the chopper plate of the chopper will affect the stability of the alkali metal laser beam quality; the pump light can only be effectively utilized when it passes through the chopper, and the pump light cannot be used when it is completely blocked by the chopper plate.

[0005] The use of an alkali metal vapor circulating flow system can solve the heat dissipation problem in the gas chamber. However, the processing technology of the circulating flow gas is difficult and has high requirements, the assembly and debugging process is relatively complicated, the airtightness inspection work is tedious and the cost is high and the volume is large. It is not suitable for low-power semiconductor-pumped alkali metal vapor lasers with an output power of less than 100 watts. Summary of the invention

[0006] The embodiments of the present application provide an alkali metal gas chamber, a laser emitter, and a gas chamber replacement method, which solve the problem of waste heat accumulation in the gas chamber in the prior art.

[0007] The present application provides an alkali metal gas chamber, comprising a carrier plate and a gas chamber. The carrier plate has a through hole. The gas chamber is installed in the through hole of the carrier plate. The carrier plate drives the through hole to reciprocate between a first position and a position away from the first position. The first position is the position where the laser irradiation falls on the carrier plate.

[0008] Preferably, the carrying plate is a rotating plate, and the rotating plate drives the through hole to reach the first position or move away from the first position by horizontal rotation.

[0009] Preferably, the carrying plate is driven by a motor.

[0010] Furthermore, the through holes are evenly distributed on the circumference of the movement.

[0011] Furthermore, the motor adjusts the speed of the air chamber movement.

[0012] The present application also provides an alkali metal laser, using the above-mentioned alkali metal gas chamber, and further comprising a light source, a heating device, a first resonant cavity mirror, and a second resonant cavity mirror. The light source, the first resonant cavity mirror, the rotatable alkali metal gas chamber, and the second resonant cavity mirror are sequentially installed on the light path. When the through hole is away from the light source, the disk surface of the carrier disk blocks the light source. The heating device keeps the temperature in the gas chamber not lower than the set temperature.

[0013] Preferably, the heating device is a heating sheet or a heating belt attached to the air chamber.

[0014] Preferably, the heating device is a temperature maintaining chamber. The temperature maintaining chamber is a chamber with a heating plate or a heating belt attached to the inner wall. The through hole on the carrier plate enters the temperature maintaining chamber when it is away from the first position.

[0015] Preferably, a chopper is further included. The chopper is located between the light source and the first resonant cavity mirror. When the carrier plate moves, the chopper stops moving and does not block the light path.

[0016] The present application also provides a method for replacing an alkali metal gas chamber, using the above-mentioned alkali metal laser, comprising the steps of:

[0017] The carrier plate stops moving, and the through hole where the air chamber to be replaced is located faces the light source; the chopper operates at the same frequency as the carrier plate movement to block the light.

[0018] Replace the air chamber to be replaced.

[0019] Start the movement of the carrier plate and stop the movement of the chopper.

[0020] At least one of the above technical solutions adopted in the embodiments of the present application can achieve the following beneficial effects:

[0021] The alkali metal gas chamber uses a carrier plate to drive the movement of the gas chamber, realizing the alternating heat dissipation of the alkali metal vapor in the gas chamber, and promptly solving the problem of waste heat accumulation. The alkali metal laser can replace the damaged alkali metal vapor chamber in time, which is convenient to operate without stopping the laser emission. It fully utilizes the pump light energy. It is low in cost and suitable for pulsed low-power output alkali metal lasers. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0023] Figure 1 This is a structural diagram of an alkali metal gas chamber embodiment of the present application;

[0024] Figure 2 This is a structural diagram of another alkali metal gas chamber embodiment of the present application;

[0025] Figure 3 This is a structural diagram of an alkali metal laser embodiment of the present application;

[0026] Figure 4 This is a structural diagram of another alkali metal laser embodiment of the present application;

[0027] Figure 5 This is a flow chart of an embodiment of a method for replacing an alkali metal gas chamber of the present application. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0029] The technical solutions provided by various embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0030] Figure 1 This is a structural diagram of an alkali metal gas chamber embodiment of the present application.

[0031] An alkali metal gas chamber comprises a carrier plate 1 and a gas chamber 2.

[0032] The carrying plate is provided with a through hole, and the air chamber is installed in the through hole of the carrying plate.

[0033] The gas chamber is a glass bubble filled with alkali metal vapor and buffer gas or a closed metal cavity equipped with a window piece.

[0034] For example, the carrier plate is made of aluminum, and the front and back surfaces of the through holes are sealed by installing transparent window sheets to form a closed metal cavity.

[0035] The carrying plate drives the through hole to reciprocate between the first position and away from the first position.

[0036] The first position is the position where the laser irradiates the landing point on the carrier plate. The carrier plate drives the through hole to reciprocate between the first position and away from the first position, so that the air chamber can dissipate the waste heat generated by the light irradiation of the air chamber 4 when it is away from the light irradiation.

[0037] like Figure 1 As shown, the reciprocating motion of the carrier plate may be:

[0038] (1) Up and down translation;

[0039] (2) Rotation;

[0040] Other forms of movement are also possible. Preferably, the carrier plate rotates around the rotation axis. The distance between the through hole on the carrier plate and the rotation axis is fixed.

[0041] The carrying plate is a rotating plate, and the rotating plate drives the through hole to reach the first position or move away from the first position by horizontal rotation.

[0042] For example, the carrier plate is a rotating plate, and there is one or more through holes for accommodating the air chambers on a circumference of the rotating plate at equal distances from the rotation center. The rotation of the rotating plate drives the air chambers to reciprocate between facing the light and away from the light.

[0043] When the carrier disk rotates, light will illuminate the disk surface between the through holes, which will turn the originally continuous light into pulsed light. In order to make the frequency of the pulsed light consistent, the through holes are further evenly distributed on a circle with the rotation axis as the center.

[0044] Figure 2 This is a structural diagram of another alkali metal gas chamber embodiment of the present application.

[0045] The carrier plate is driven by a motor 3. The carrier plate is controlled to move by the motor. Preferably, the motor adjusts the speed of the air chamber movement. By adjusting the speed of the air chamber movement, the frequency and duty cycle of the pulse light are changed, so as to output alkali metal lasers with different pulse frequencies and duty cycles.

[0046] For example, there is a round hole in the center of the turntable, which is used to install a motor, and the motor drives the turntable to rotate. The rotation speed of this motor can be adjusted.

[0047] Figure 3 This is a structural diagram of an alkali metal laser embodiment of the present application.

[0048] The present application also provides an alkali metal laser, which uses the above-mentioned alkali metal gas chamber and also includes a light source 5, a heating device 6, a first resonant cavity mirror 5 and a second resonant cavity mirror 7.

[0049] The light source, the first resonant cavity mirror, the rotatable alkali metal gas chamber and the second resonant cavity mirror are sequentially installed on the laser path.

[0050] The light source is a laser transmitter, and a pump laser or other lasers capable of generating alkali metal lasers may be selected, which is not further limited here.

[0051] The light source is directly opposite to the first position. When the through hole is far away from the light source, the disk surface of the carrier disk blocks the light source.

[0052] When the through hole is away from the light source, the surface of the carrier plate blocks the light source until the through hole faces the light source again. The carrier plate then assumes the original role of a chopper, converting the laser passing through the carrier plate from continuous light to pulsed light.

[0053] For example, the carrier plate is located between two resonant cavity mirrors. Each air chamber moves between the two resonant cavity mirrors to form a resonant cavity, realizes the absorption of pump light and the output of alkali metal laser during the working time of forming the resonant cavity, and releases waste heat during the waiting time after the currently working air chamber rotates out of the resonant cavity.

[0054] The gas chamber needs to ensure that the alkali metal is maintained in a gaseous state, so a heating device is required to heat the gas chamber. Preferably, the heating device is a heating sheet 6-1 or a heating belt attached to the gas chamber.

[0055] For example, the heating sheet or heating belt is installed on the outer wall of the air chamber. If it is installed on the outer wall through which light passes, the heating sheet or heating belt has a hole for light transmission.

[0056] Figure 4 This is a structural diagram of another alkali metal laser embodiment of the present application.

[0057] The heating device can also be a temperature-maintaining cavity 6-2. The temperature-maintaining cavity is a cavity with a heating plate or a heating belt attached to the inner wall. The through hole on the carrier plate enters the temperature-maintaining cavity when it is away from the first position.

[0058] For example, since the through hole on the carrier plate will reciprocate between the first position and away from the first position, the purpose of the through hole on the carrier plate away from the first position is to dissipate the waste heat generated by the light irradiating the air chamber in the alkali metal vapor in the air chamber. Therefore, when the through hole on the carrier plate dissipates heat away from the first position, it passes through a semi-sealed temperature maintenance chamber. The temperature maintenance chamber is a cavity with an opening, and a heating device, such as a heating plate or a heating belt, is installed on the inner wall of the cavity. When the through hole on the carrier plate passes through the temperature maintenance chamber, the waste heat is dissipated, but the temperature will be maintained above a fixed value, which is the lowest temperature at which the alkali metal maintains a vapor state.

[0059] The temperature of the heating device is controlled by a temperature controller to maintain the temperature in the gas chamber so that the alkali metal remains in a vapor state without condensation.

[0060] The optical chopper is also included. The optical chopper is located between the light source and the first resonant cavity mirror. When the carrier plate moves, the optical chopper stops moving and does not block the light path.

[0061] By installing an additional chopper, when replacing air chambers on a carrier plate with more than one air chamber, the laser can be continuously generated while the air chambers are replaced.

[0062] Figure 5 This is a flow chart of an embodiment of a method for replacing an alkali metal gas chamber of the present application.

[0063] A method for replacing an alkali metal gas chamber, using the above-mentioned alkali metal laser, is usually used in the case of long-term operation, comprising the steps of:

[0064] 101. The carrier plate stops moving, and the through hole where the air chamber to be replaced is located faces the light source; the chopper operates at the same frequency as the carrier plate movement to block the light.

[0065] Since the carrier plate stops moving and the air chamber on the through hole is facing the light source, continuous light rather than pulsed light is generated at this time. The chopper rotates at the same frequency to block the light when the carrier plate stops moving, so that the laser finally emitted from the device is still pulsed light.

[0066] 102. Replace the air chamber to be replaced.

[0067] Replacing the air chamber that needs to be replaced will not affect the operation of the air chamber facing the light source.

[0068] 103. Start the movement of the carrier plate and stop the movement of the chopper.

[0069] After the air chamber is replaced, the carrier plate is started to move, and the chopper is notified to stop moving. The chopping work is transferred from the chopper to the carrier plate. The replacement of the air chamber is completed.

[0070] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. An alkali metal laser, characterized in that: It comprises an alkali metal gas chamber, a light source, a heating device, a first resonant cavity mirror and a second resonant cavity mirror; The light source, the first resonant cavity mirror, the rotatable alkali metal gas chamber, and the second resonant cavity mirror are sequentially installed on the light path; When the through hole is far away from the light source, the disk surface of the carrier disk blocks the light source; The heating device keeps the temperature in the air chamber not lower than the set temperature; The alkali metal gas chamber comprises a carrier plate and a gas chamber; The carrying plate is provided with a through hole; The air chamber is installed in the through hole of the carrying plate; The carrying plate drives the through hole to reciprocate between the first position and away from the first position; The first position is the position where the laser irradiation lands on the carrier plate; The heating device is a temperature maintaining chamber, which is a cavity with an opening. When the through hole on the carrier plate is away from the first position to dissipate heat, the temperature is maintained at a fixed value through the semi-sealed temperature maintaining chamber.

2. The alkali metal laser according to claim 1, characterized in that: The carrying plate is a rotating plate, and the rotating plate drives the through hole to reach the first position or move away from the first position by horizontal rotation.

3. The alkali metal laser according to claim 1, characterized in that: The carrying plate is driven by a motor.

4. The alkali metal laser according to claim 2, characterized in that: The through holes are evenly distributed on the circumference of the movement.

5. The alkali metal laser according to claim 3, characterized in that: The motor adjusts the speed of the air chamber movement.

6. The alkali metal laser according to claim 1, characterized in that: The temperature of the heating device is controlled by a temperature controller to maintain the temperature in the gas chamber so that the alkali metal remains in a vapor state without condensation.

7. The alkali metal laser according to claim 1, characterized in that: The heating device is a heating sheet or a heating belt attached to the air chamber.

8. The alkali metal laser according to claim 1, characterized in that: The heating device is a temperature maintaining chamber; The temperature-maintaining cavity is a cavity with a heating plate or a heating belt attached to the inner wall; The through hole on the carrying plate enters the temperature maintaining chamber when it is away from the first position.

9. The alkali metal laser according to claim 1, characterized in that: Also includes a chopper; The chopper is located between the light source and the first resonant cavity mirror; When the carrier plate moves, the chopper stops moving and does not block the light path.

10. A method for using an alkali metal laser, using the alkali metal laser according to any one of claims 1 to 9, characterized in that: Contains steps: The carrier plate drives the through hole to reciprocate between the first position and away from the first position; the first position is the position where the laser irradiation falls on the carrier plate; When the through hole on the carrier plate is away from the first position to dissipate heat, the temperature is maintained at a fixed value through the semi-sealed temperature maintaining chamber.

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