CN106025785B - Mixed electrode pockels cell and time-sharing loop-dividing driving method - Google Patents
Mixed electrode pockels cell and time-sharing loop-dividing driving method Download PDFInfo
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- CN106025785B CN106025785B CN201610566944.4A CN201610566944A CN106025785B CN 106025785 B CN106025785 B CN 106025785B CN 201610566944 A CN201610566944 A CN 201610566944A CN 106025785 B CN106025785 B CN 106025785B
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/10—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
- H01S3/11—Mode locking; Q-switching; Other giant-pulse techniques, e.g. cavity dumping
- H01S3/1123—Q-switching
- H01S3/115—Q-switching using intracavity electro-optic devices
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/10—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
Abstract
The invention discloses a mixed electrode pockels cell and a time-sharing loop-dividing driving method thereof, which realize the high-efficiency cooling and low-voltage quick response driving of the pockels cell, the basic structure of the mixed electrode pockels cell is a sandwich structure formed by a discharge cavity and a high-reflection mirror clamping a z-cut DKDDP crystal, the longitudinal electro-optical effect is used and the longitudinal conduction cooling is carried out, the discharge cavity is used as a laser incidence side electrode, the high-reflection mirror has the functions of a reflector, a heat sink and an electrode, the aperture of the pockels cell can be scaled and amplified, the high-average power density can be borne, the high-flux repetition frequency operation can be carried out, the driving voltage is low, the response time is quick, and the mixed electrode pockels cell is suitable.
Description
Technical Field
The invention belongs to the technical field of high-energy repetition frequency laser, and particularly relates to a mixed electrode pockels cell which is applicable to a high-energy repetition frequency laser system and has a caliber capable of being scaled and amplified, can bear high average power density and can run at a high-flux repetition frequency, and a time-sharing and loop-dividing driving method of the pockels cell.
Background
In recent years, the diode-pumped high-energy repetition frequency solid laser technology is rapidly developed under the promotion of the requirements of high-energy density physical research and fusion energy research, and the output of about 100J and 10Hz is realized at present. Limited by diode pumping power, laser drivers generally employ gain media with long upper energy level lifetime, which means a small stimulated emission cross-section according to einstein radiation theory, and usually require multi-pass amplification in order to efficiently extract stored energy in the gain media. The Pockels cell is a key device for supporting a multi-pass amplification scheme, and is used for controlling the amplification pass number of laser pulses by being matched with a polaroid for leading in/out of the laser pulses and inhibiting self-excited oscillation in a multi-pass amplification cavity.
Under the application of high-energy repetition frequency, the specific requirements on the Pockels cell include: the light-passing aperture can be scaled and amplified to several centimeters or even tens of centimeters, can bear the average power density of laser of dozens of W/cm2, the damage threshold value reaches several J/cm2, the switch rise time is within several ns, and the frequency operation can be repeated. The ratio of the longitudinal length of a crystal to the aperture of a transverse light-transmitting aperture of a traditional ring electrode pockels cell is usually larger than 2:1 due to the requirement of electric field uniformity, high absorption loss is caused by a long crystal with a large aperture, and in addition, serious heat effect is further generated by absorption heat generation under high average power density, so that the ring electrode pockels cell becomes unrealistic in high-energy repetition frequency application. The uniformity of the transversely excited Pockels cell electric field is irrelevant to the thickness of the crystal, but the half-wave voltage of the Pockels cell electric field is in direct proportion to the aperture of the light passing and in inverse proportion to the thickness of the crystal, and the Pockels cell has very high half-wave voltage due to large-aperture application and thermally required thin crystals, so that the difficulty in developing a fast-response high-voltage power supply is greatly increased. In addition, in lateral applications, the crystals have natural birefringence, and in high-energy repetition frequency applications, two identical crystals must be used for thermal compensation.
The concept of the thin-film electrode pockels cell (HEPC), a Hybrid-electrode pockels cell, is proposed in an article named Compact Efficient Laser system for Laser Fusion Energy, (Compact Efficient Laser Systems Required for Laser infusion Fusion Energy, a. bayramian, s. aces, t. anklam, et al, Fusion and Technology,60(1), 28-48.2011) by liprmor national laboratory a.bayramian in 2011 (Compact Efficient Laser system for Laser Fusion Energy), which is used longitudinally, using a transparent conductive film of ITO as the electrode to which the switching voltage pulse is applied, electro-optic crystals are cooled laterally by high-speed He gas, can be scaled to large calibers, and absorption is reduced using thin crystals; however, the damage threshold of the ITO conductive film is low, about 1J/cm2, which limits the flux design point of a laser system, and meanwhile, ITO has large absorption to laser, which results in large insertion loss of a Pockels cell, and in addition, a high-speed He gas is used for cooling crystals to avoid the thermal effect under the application of high-level power, and the cooling system is complex. Zhang Jun et al, a research center of laser fusion of the Chinese institute, in 2011 proposed a scheme of a reflective plasma electro-optical switch in a patent of reflective plasma electro-optical switch (patent number: ZL201010003664.5), the switch is designed in a reflective mode, an electric field is longitudinally applied, and the switch is cooled in a longitudinal conduction mode, and has the characteristics of being capable of scaling and amplifying a caliber and being high in cooling efficiency. The switch crystal and the heat sink are sealed by adopting a direct contact mechanical compression method, and the direct contact sealing method has the following problems: the damage problem of a sol-gel antireflection film layer plated on a crystal; the stress generated in the compressed crystal reduces the static extinction ratio of the switch; thermal stress due to limited thermal expansion of the crystal in high average power applications results in large thermal depolarization losses of the switch. In addition, the switch uses metal as the back electrode, which has the advantages of good electrical conductivity and high thermal conductivity, but the switch can not be applied to high flux conditions because the damage threshold is too low when the switch is used as a reflector.
Disclosure of Invention
In view of the problems in the prior art, the invention provides a pockels cell with a hybrid electrode and a time-sharing shunt loop driving method, wherein the aperture of the pockels cell can be scaled and amplified, can bear high average power density, can operate at high flux repetition frequency, is suitable for a high-energy repetition frequency laser system, and supports multi-pass amplification. The DKDP crystal and the high-reflection mirror are in conduction sealing through thin mixed gas, damage and stress accumulation of a crystal anti-reflection film layer caused by direct contact sealing are avoided, and the time-sharing branch loop driving method has the characteristics of low driving voltage and short response time.
In order to achieve the purpose, the invention provides the following technical scheme: a mixed electrode Pockels cell comprises a Pockels cell shell, an optical window, a discharge cavity, a DKDP crystal, a high-reflection mirror, a conical discharge needle, an electrode ring, an electrode seat, an air inlet and suction nozzle, a circuit module and a temperature control module;
the pockels cell is characterized in that an air inlet and exhaust nozzle is arranged on the pockels cell shell and communicated with a discharge cavity, an optical window is arranged outside the discharge cavity, an electrode ring is arranged in the discharge cavity, a conical discharge needle is arranged in the electrode ring, the electrode ring is connected with the inner end of an electrode holder, and the electrode holder is connected with the pockels cell shell;
a round hole is formed in the shell of the Pockels cell, the DKDP crystal is embedded in the round hole, a high-reflection mirror and a discharge cavity are respectively arranged on two surfaces of the DKDP crystal, a metal gasket is further arranged in the shell of the Pockels cell, the metal gasket is located between the DKDP crystal and the high-reflection mirror, and a gap is formed between the DKDP crystal and the high-reflection mirror;
one surface of the high-reflection mirror is plated with a laser high-reflection film, the other surface of the high-reflection mirror is plated with a gold film, one surface of the high-reflection mirror, which is plated with the laser high-reflection film, faces to one side of the DKDP crystal, the surface plated with the gold film is attached to the temperature control module, and the surface of the high-reflection mirror, which is plated with the gold film, is connected with the metal gasket circuit;
the circuit module comprises a matching resistor and a voltage-dividing capacitor, and the voltage-dividing capacitor is connected with the Pockels cell in series through a terminal and then is connected with the matching resistor in parallel.
Further, the circuit module still includes the cable seat, the terminal includes first terminal, second terminal, third terminal and fourth terminal, voltage-dividing capacitor's one end is passed through the third terminal and is connected with the electrode holder outer end of pockels box, voltage-dividing capacitor's the other end and matching resistance are connected to be connected and the high voltage through first terminal and cable seat cable core, matching resistance's the other end is connected through one side and the metal gasket that the fourth terminal and the high anti-mirror of pockels box plated the gold film to be connected and ground connection through second terminal and cable seat cable sheath.
Further, the gap is filled with a mixed gas of He and Ne of 500Pa to 5000 Pa.
Furthermore, the discharge cavity is filled with mixed gas of He and Ne of 500 Pa-5000 Pa, and is statically sealed through the air inlet and exhaust nozzle.
Furthermore, silica gel is adopted for vacuum sealing between the optical window and the Pockels cell shell, between the DKDP crystal and the Pockels cell shell, and between the high-reflection mirror and the Pockels cell shell.
Furthermore, the temperature control module comprises a TEC, a thermocouple, a heat insulation layer and heat dissipation fins, wherein the TEC is positioned in a central hole of the heat insulation layer, a cold surface of the TEC is bonded with the high-reflection mirror, a hot surface of the TEC is bonded with the heat dissipation fins through heat conduction silicone grease, the thermocouple is positioned in a small hole of the heat insulation layer, and the thermocouple is bonded with the high-reflection mirror through the heat conduction silicone grease.
A time-sharing and loop-dividing driving method of a mixed electrode Pockels cell, wherein the mixed electrode Pockels cell is the mixed electrode Pockels cell, and the method comprises the following steps:
s1: applying high-voltage switch voltage pulse on a discharge electrode of a mixed electrode pockels cell and a high-reflector gold film, wherein in the initial loading stage, the voltage is lower, He and Ne mixed gas in a discharge cavity and a gap is not broken down, and a series circuit is formed by a voltage-dividing capacitor, a DKDP crystal, an equivalent resistor of the high-reflector and a capacitor and is connected with a matching resistor in parallel;
s2: forming a strong electric field by using the increased switching voltage pulse voltage, puncturing the mixed gas of He and Ne in the discharge cavity and the mixed gas of He and Ne in the gap, forming uniform, transparent, high-conductivity and full-aperture covered plasma, and enabling the equivalent resistance and the capacitance of the high-reflection mirror to be short-circuited;
s3: the DKDP crystal is charged to a quarter wave voltage by switching voltage pulses through plasmas formed on two sides of the DKDP crystal, so that equivalent capacitor voltage division and equivalent resistor current limiting of a high-reflection mirror are avoided, and low-voltage quick response driving of the Pockels cell is achieved.
The invention has the following beneficial effects:
(1) the front surface of the high-reflection mirror is plated with a high-threshold laser reflection film, and the rear surface of the high-reflection mirror is plated with a gold film, so that the high-reflection mirror has the functions of a reflector, a heat sink and an electrode. A gap with hundred-micron magnitude is formed between the high-reflection mirror and the DKDP crystal, He and Ne mixed gas is filled in the gap, and gas molecules realize conduction heat exchange between the high-reflection mirror and the DKDP crystal, so that the silicon-based high-reflection mirror with high heat conductivity can longitudinally conduct and cool the DKDP crystal, damage to a crystal anti-reflection film layer and clamping stress caused by direct contact sealing are avoided, and stress accumulation caused by limited thermal expansion of the crystal is reduced.
(2) The limiting factors of the clear aperture of the Pockels cell mainly comprise driving voltage, electric field uniformity and heat exchange efficiency, the Pockels cell of the invention longitudinally applies switching voltage pulse, and the driving voltage is irrelevant to the size of the clear aperture and the thickness of a crystal; the laser incidence side electrode is transparent plasma, the back side electrode is a gold film plated on the high-reflection mirror, and the distribution uniformity of an electric field in the crystal is not limited by the aperture of the light transmission; the cooling mode is longitudinal conduction cooling, heat is transferred along the longitudinal direction, and the heat exchange efficiency is not limited by the aperture of the transverse light, so that the pockels cell has the characteristic that the aperture can be scaled and amplified.
(3) Under the operation of high-energy repetition frequency, due to the linear absorption of laser by the electro-optic crystal, thermal deposition is generated in the crystal, so that adverse thermal effects such as cracking of an anti-reflection film layer of the crystal, thermal depolarization, thermal wavefront distortion and the like are caused. The direct method for reducing the heat effect is to select crystals with small absorption coefficient and reduce the thickness of the crystals in the light transmission direction, and the DKDP crystals are the best choice so far in consideration of factors such as crystal growth, processing, coating technology and the like. The pockels cell of the invention applies switching voltage pulse longitudinally, the driving voltage is irrelevant to the thickness of the crystal, therefore, the crystal as thin as possible can be selected, in addition, the pockels cell of the invention conducts and cools longitudinally, it has the characteristics of large heat exchange area, short heat conduction path and small transverse temperature gradient, the heat effect of the pockels cell can be managed efficiently, in conclusion, the pockels cell of the invention can be applied to high-energy repetition frequency laser system and bear high average power density of laser.
(4) The high-reflection mirror adopts a non-metal material as a substrate, and the laser reflection film and the electrode gold film are plated in a split-surface mode, so that the mixed electrode pockels cell can be used under a high-flux condition. In order to avoid equivalent capacitance voltage division and equivalent resistance current limitation of a nonmetal high-reflection mirror, the time-sharing branch loop driving method realizes low-voltage quick response driving of the Pockels cell.
Drawings
FIG. 1 is a schematic diagram of a hybrid electrode pockels cell structure according to the present invention;
FIG. 2 is a schematic diagram of a circuit module according to the present invention;
FIG. 3 is a schematic diagram of a time-sharing loop driving circuit according to the present invention;
FIG. 4 is a graph showing the variation of driving voltage of a pockels cell with time for a hybrid electrode according to the present invention;
FIG. 5 shows the measurement results of rising time of pockels cell of the hybrid electrode according to the present invention;
FIG. 6 is a graph showing the relationship between temperature rise and thermal depolarization loss with time under 110W laser irradiation (35W/cm2@ phi 20mm) in accordance with the present invention;
in the figure: 1-pockels case shell, 2-DKDP crystal, 3-optical window, 4-high reflection mirror, 5-electrode holder, 6-air suction nozzle, 7-discharge cavity, 8-conical discharge needle, 9-electrode ring, 10-round hole, 11-metal gasket, 12-TEC, 13-heat insulation layer, 14-thermocouple, 15-heat radiation fin;
wherein, the abscissa of fig. 4 represents time in ns, and the ordinate represents voltage in kV; FIG. 5 shows time in ns on the abscissa and normalization on the ordinate; in fig. 6, the abscissa represents time in minutes, the primary axis of ordinate represents thermal depolarization, and the secondary axis of ordinate represents temperature rise in K.
Detailed Description
In order to make the technical solutions of the present invention better understood, the following description of the technical solutions of the present invention with reference to the accompanying drawings of the present invention is made clearly and completely, and other similar embodiments obtained by a person of ordinary skill in the art without any creative effort based on the embodiments in the present application shall fall within the protection scope of the present application.
The first embodiment is as follows:
as shown in fig. 1, 2 and 3, a pockels cell with mixed electrodes comprises a pockels cell shell 1, an optical window 3, a discharge cavity 7, a DKDP crystal 2, a high-reflection mirror 4, a conical discharge needle 8, an electrode ring 9, an electrode holder 5, an air inlet and extraction nozzle 6, a circuit module and a temperature control module; an air inlet and exhaust nozzle 6 is arranged on the pockels cell shell 1, the air inlet and exhaust nozzle 6 is communicated with a discharge cavity 7, an optical window 3 is arranged outside the discharge cavity 7, an electrode ring 9 is arranged in the discharge cavity 7, a conical discharge needle 8 is arranged in the electrode ring 9, the electrode ring 9 is connected with the inner end of an electrode holder 5, and the electrode holder 5 is connected with the pockels cell shell 1;
the Pockels cell shell 1 is internally provided with a round hole 10, the DKDP crystal 2 is embedded in the round hole 10, two surfaces of the DKDP crystal 2 are respectively provided with a high-reflection mirror 4 and a discharge cavity 7, the discharge cavity 7 is filled with mixed gas of He and Ne of 500 Pa-5000 Pa, when the vacuum degree reaches 10-20Pa, the discharge cavity 7 is statically sealed off through an air inlet and suction nozzle 6, the Pockels cell shell 1 is also internally provided with a metal gasket 11, the metal gasket 11 is positioned between the DKDP crystal 2 and the high-reflection mirror 4, a gap is formed between the DKDP crystal 2 and the high-reflection mirror 4, the gap is filled with mixed gas of He and Ne of 500 Pa-5000 Pa, and the conduction and heat exchange between the DKDP crystal 2 and the high-reflection mirror 4 are realized through the mixed gas, so that the silicon-based high-reflection mirror 4 with high thermal conductivity can longitudinally conduct and cool the DKDP crystal 2, and the damage and stress of a reflection reducing film layer caused by, and reduces stress accumulation caused by crystal thermal expansion limitation, so that the Pockels cell can operate at high flux.
A surface of high anti-mirror 4 has plated the high anti-membrane of laser, another surface of high anti-mirror 4 has plated the gold film, and high anti-mirror 4 has plated the high one side of anti-membrane of laser towards DKDP crystal one side, has plated the one side and the temperature control module laminating of gold film, high anti-mirror 4 has plated the one side and the metal gasket 11 of gold film and is connected on the circuit, between optical window 3 and the pockels box casing 1, between DKDP crystal 2 and the pockels box casing 1, all adopt silica gel to carry out vacuum sealing between high anti-mirror 4 and the pockels box casing 1.
The circuit module includes matching resistor and divider capacitance, divider capacitance C0 pass through after terminal and HEPC establish ties and with matching resistor Rmat parallel connection, circuit module still includes the cable seat, the terminal includes first terminal, second terminal, third terminal and fourth terminal, divider capacitance C0's one end is connected with HEPC's electrode holder outer end through the third terminal, divider capacitance C0's the other end is connected with matching resistor Rmat to be connected and connect high voltage through first terminal and cable seat cable core, matching resistor Rmat's the other end is connected through fourth terminal and HEPC's high anti-mirror 4 one side and metal shim 11 that have plated the gold film to be connected and ground connection with the cable seat cable sheath through the second terminal.
The temperature control module comprises a TEC12, a thermocouple 14, a heat insulation layer 13 and heat dissipation fins 15, the TEC12 is positioned in a central hole of the heat insulation layer 13, a cold surface of the TEC12 is bonded with the high-reflection mirror 4, and a hot surface of the TEC12 is bonded with the heat dissipation fins 15 by adopting heat conduction silicone grease; the thermocouple 14 is positioned in a small hole of the heat insulation layer 13, and the thermocouple 14 is bonded with the high-reflection mirror 4 by adopting heat conduction silicone grease. The semiconductor cooler (TEC)12 is made by using the peltier effect of semiconductor materials, which is a phenomenon that when a direct current passes through a couple composed of two semiconductor materials, one end absorbs heat and the other end releases heat.
A time-sharing loop-dividing driving method of a mixed electrode Pockels cell is characterized in that a high-reflection mirror gold film is electrically connected with a metal gasket 11, a gap between a DKDP crystal 2 and a high-reflection mirror 4 is equivalent to a spark gap Switch, a Switch voltage pulse is loaded through a discharge electrode and the high-reflection mirror gold film before gas breakdown, and the Switch voltage pulse charges the DKDP crystal 2 through plasmas in a discharge cavity 7 and in the gap after the gas breakdown, and specifically comprises the following steps:
s1: high-voltage switch voltage pulses are applied to the discharge electrode and the high-reflection mirror gold film on the mixed electrode pockels cell, the voltage is lower at the initial loading stage, He and Ne mixed gas in the discharge cavity 7 and the gap is not broken down, and a series circuit is formed by a voltage dividing capacitor C0, a DKDP crystal, an equivalent resistor RM of the high-reflection mirror 4 and a capacitor CM and is connected with a matching resistor Rmanth in parallel;
s2: forming a strong electric field by using the increased pulse voltage of the switching voltage, puncturing the mixed gas of He and Ne in the discharge cavity 7 and the mixed gas of He and Ne in the gap, forming uniform, transparent, high-conductivity and full-aperture-covered plasma, and enabling the equivalent resistance RM and the capacitance CM of the high-reflection mirror 4 to be short-circuited;
s3: the DKDP crystal 2 is charged to a quarter wave voltage by switching voltage pulses through plasmas formed on two sides of the DKDP crystal 2, so that the equivalent capacitor CM voltage division and the equivalent resistor RM current limiting of the high-reflection mirror 4 are avoided, and the low-voltage quick response driving of the Pockels cell is realized.
In the invention, the pockels cell is used for controlling the polarization direction of incident laser, so that the pockels cell is matched with a polaroid sheet to realize on-off control of an optical path or propagation direction control of laser. The working principle is as follows: in a static state, linearly polarized light sequentially vertically transmits the light window 3 and the DKDP crystal 2, and then incident laser is reflected by the high-reflection mirror 4 and returns along an original light path. In dynamic state, before laser comes, the switch voltage pulse generator receives trigger signal and outputs switch voltage pulse. The switching voltage pulse is applied to the discharge electrode and the high-reflection mirror gold film, the mixed gas of He and Ne in the discharge cavity 7 and the conduction gap is broken down to form uniform, high-conductivity, transparent and full-aperture-covered plasma, and then the switching voltage pulse is loaded on the DKDP crystal 2 through the plasma and charges the DKDP crystal 2. If the voltage amplitude loaded on the DKDP crystal 2 is a quarter-wave voltage, after incident laser light penetrates through the polarized crystal, linearly polarized light is changed into circularly polarized light, the circularly polarized light penetrates through the polarized crystal again after being reflected by the high-reflection mirror 4, the circularly polarized light is changed into the linearly polarized light, at the moment, the polarization direction of emergent light rotates 90 degrees relative to the polarization direction of the incident laser light, and the laser light is reflected out of an original light path when reaching a polarizing plate. In summary, by controlling the switching voltage pulse, the pockels cell can be matched with the polarizer to realize on-off control of the optical path and control of the propagation direction.
Comparison experiment one:
in order to investigate the performance of the high average power mixed electrode pockels cell, a 30mm caliber prototype was developed and tested. The insertion loss is less than 1.5%, the static extinction ratio in the full aperture is better than 3dB, and the switching efficiency is more than or equal to 99.6%. Fig. 4 is a time-dependent variation of the driving voltage of the pockels cell with the mixed electrode, at the leading edge of the switching voltage pulse, as the voltage increases, the strong electric field causes the breakdown of the working gas in the discharge chamber 7 and the gap, and then starts to charge the crystal, after the crystal charging is completed, the voltage loaded on the pockels cell with the mixed electrode is about 10.5kV, the duration of the 10.5kV plateau voltage is about 200ns, and then the voltage loaded on the pockels cell gradually recovers to 0 kV. FIG. 5 shows the rise time of the pockels cell for the hybrid electrode of the present invention, where the response time is about 6.5 ns; FIG. 6 shows the relationship between temperature rise and thermal depolarization loss with time under 110W laser irradiation (35W/cm2@ phi 20mm), and about 7 minutes after the laser is turned on, the DKDP crystal reaches a thermal equilibrium state, the maximum temperature rise in the crystal is 3.6K, and the thermal depolarization loss is less than 1.0%; and (3) turning off the laser at the moment of 20 minutes, rapidly reducing the thermal depolarization loss to about 0.1%, and gradually recovering the temperature rise in the crystal to 0 ℃.
Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.
Claims (4)
1. A mixed electrode pockels cell is characterized by comprising a pockels cell shell, an optical window, a discharge cavity, a DKDP crystal, a high-reflection mirror, a conical discharge needle, an electrode ring, an electrode seat, an air inlet and exhaust nozzle, a circuit module and a temperature control module;
the pockels cell is characterized in that an air inlet and exhaust nozzle is arranged on the pockels cell shell and communicated with a discharge cavity, an optical window is arranged outside the discharge cavity, an electrode ring is arranged in the discharge cavity, a conical discharge needle is arranged in the electrode ring, the electrode ring is connected with the inner end of an electrode holder, and the electrode holder is connected with the pockels cell shell;
the device comprises a Pockels cell shell, a DKDP crystal, a metal gasket, a gap, He and Ne mixed gas, wherein a round hole is formed in the Pockels cell shell, the DKDP crystal is embedded in the round hole, a high-reflection mirror and a discharge cavity are respectively arranged on two surfaces of the DKDP crystal, the metal gasket is arranged in the Pockels cell shell and is positioned between the DKDP crystal and the high-reflection mirror, the gap is formed between the DKDP crystal and the high-reflection mirror, the He and Ne mixed gas of 500 Pa-5000 Pa is filled in the gap, the He and Ne mixed gas of;
one surface of the high-reflection mirror is plated with a laser high-reflection film, the other surface of the high-reflection mirror is plated with a gold film, one surface of the high-reflection mirror, which is plated with the laser high-reflection film, faces to one side of the DKDP crystal, the surface plated with the gold film is attached to the temperature control module, and the surface of the high-reflection mirror, which is plated with the gold film, is connected with the metal gasket circuit;
the circuit module comprises a matching resistor and a voltage division capacitor, and the voltage division capacitor is connected with the Pockels cell in series through a terminal and then is connected with the matching resistor in parallel;
high-voltage switch voltage pulse is applied to a discharge electrode of a pockels cell of a mixed electrode and a gold film of a high-reflector, the voltage is lower at the initial loading stage, mixed gas of He and Ne in a discharge cavity and a gap is not broken down, a series circuit is formed by a voltage dividing capacitor, a DKDP crystal, an equivalent resistor of the high-reflector and a capacitor and is connected with a matching resistor in parallel, a strong electric field is formed by using the increased switch voltage pulse voltage, the mixed gas of He and Ne in the discharge cavity and the mixed gas of He and Ne in the gap are broken down, plasma which is uniform, transparent, high in conductivity and covers the full aperture is formed, the equivalent resistor and the capacitor of the high-reflector are short-circuited, and the DKDP crystal is charged to quarter-wave voltage by using the plasma formed on two sides of the DKDP crystal through the switch voltage pulse, so that the voltage division.
2. A hybrid electrode Pockels cell as claimed in claim 1, wherein the circuit module further comprises a cable holder, the terminals comprising a first terminal, a second terminal, a third terminal and a fourth terminal,
the one end of partial pressure electric capacity is connected with the electrode holder outer end of pockels 'box through the third terminal, partial pressure electric capacity's the other end and matching resistance are connected to be connected and connect the high voltage through first terminal and cable seat cable core, matching resistance's the other end is connected through one side and the metal gasket that gold film was plated to the high anti-mirror of fourth terminal and pockels' box to be connected and ground connection through second terminal and cable seat cable sheath.
3. The pockels cell of claim 1, wherein the optical window and the pockels cell enclosure, the DKDP crystal and the pockels cell enclosure, and the high-reflectivity mirror and the pockels cell enclosure are vacuum sealed with silicone.
4. The hybrid electrode pockels cell of claim 1, wherein the temperature control module comprises a TEC, a thermocouple, a heat insulating layer, and heat dissipating fins, the TEC is located in a central hole of the heat insulating layer, a cold surface of the TEC is bonded to the high-reflection mirror, a hot surface of the TEC is bonded to the heat dissipating fins with thermal grease, the thermocouple is located in a small hole of the heat insulating layer, and the thermocouple is bonded to the high-reflection mirror with thermal grease.
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| CN108983537A (en) * | 2017-05-31 | 2018-12-11 | 深圳市光峰光电技术有限公司 | Heat exchanger and projection device |
| CN114740641B (en) * | 2022-06-09 | 2022-11-22 | 成都凯天电子股份有限公司 | Ultraviolet light switch and laser scanning system formed by same |
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| CN2590222Y (en) * | 2002-12-18 | 2003-12-03 | 山东大学 | Pockel Cells having tapering electrode |
| DE20318348U1 (en) * | 2003-11-25 | 2005-04-14 | Linos Photonics Gmbh & Co. Kg | Electro-optical element |
| CN101672986A (en) * | 2008-12-08 | 2010-03-17 | 高培良 | An optical apparatus integrating a light isolator, a switch, an adjustable optical attenuator or a modulator |
| CN205828874U (en) * | 2016-07-19 | 2016-12-21 | 中国工程物理研究院激光聚变研究中心 | A kind of mixed electrode Pockers cell |
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| US3679289A (en) * | 1970-08-24 | 1972-07-25 | Robert L Goldstein | Crystal light modulator providing both aperture and intensity control |
| CN2590222Y (en) * | 2002-12-18 | 2003-12-03 | 山东大学 | Pockel Cells having tapering electrode |
| DE20318348U1 (en) * | 2003-11-25 | 2005-04-14 | Linos Photonics Gmbh & Co. Kg | Electro-optical element |
| CN101672986A (en) * | 2008-12-08 | 2010-03-17 | 高培良 | An optical apparatus integrating a light isolator, a switch, an adjustable optical attenuator or a modulator |
| CN205828874U (en) * | 2016-07-19 | 2016-12-21 | 中国工程物理研究院激光聚变研究中心 | A kind of mixed electrode Pockers cell |
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| CN106025785A (en) | 2016-10-12 |
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