CN1604407A

CN1604407A - A Q-modulating pool for pulsed laser

Info

Publication number: CN1604407A
Application number: CN 200410061022
Authority: CN
Inventors: 程祖海; 陈良才
Original assignee: Huazhong University of Science and Technology
Current assignee: Huazhong University of Science and Technology
Priority date: 2004-10-29
Filing date: 2004-10-29
Publication date: 2005-04-06
Anticipated expiration: 2024-10-29
Also published as: CN1283029C

Abstract

It is an impulse laser Q adjusting pool belonging to laser technique, which has the following: inner cylinder with both ends sealed with flange, where locates a focus lens at center holes of two flanges and a racket connected with the flange inside the inner cylinder with a calibration lens; an outer cylinder outside the inner cylinder to form a clamp cover between inner and outer cylinders; a ultra-limit fluid joint tube on the walls of inner cylinder to connect ultra-limit fluid generator; temperature constant joint tube and exit tube on the walls of outer cylinder.

Description

The accent Q pond that a kind of pulse laser is used

Technical field

The invention belongs to laser technology field, the Q-modulating device that particularly a kind of pulse laser is used.

Background technology

An effective way that improves pulsed laser energy and peak power is to transfer Q, with widely used CO ₂Pulse laser is an example, and it is to place a dye Q box in resonant cavity that its tradition is transferred the Q mode, and this accent Q box is the disc box body with logical light window, and logical light window is sealed by level crossing; The Q value of laser depends on the saturated absorption light intensity Is of box inner dye, and needed Is will obtain by the concentration that changes dyestuff.The problem that the method transfers Q to exist is: after (1) accent Q box was closed and puts resonant cavity into, dye strength just can't change; (2) external factor such as intense laser radiation can make dyestuff rotten gradually, influences the stability of Q value; (3) after the dye deterioration, transfer the Q box if change, then need to take apart resonant cavity, it is very inconvenient to waste time and energy.

Summary of the invention

The present invention proposes the accent Q pond that a kind of pulse laser is used, and the problem that adopts the passive type saturated absorption to transfer Q to exist at existing Q-switched laser is set in real time or changed Q value realizing, and the inconvenience that can avoid setting the drift of Q value and take resonant cavity replacing accent Q box apart.

The accent Q pond that a kind of pulse laser of the present invention is used, has cylindrical shell by the optical frames sealing, it is characterized in that: described cylindrical shell is an inner barrel, its two ends encapsulation flange, two flange center's lead to the hole site all are equipped with condenser lens, and the tubular bearing that is connected with flange is positioned at inner barrel, bearing one end is equipped with collimating lens; Be with outer cylinder body outside the inner barrel, form chuck between the inside and outside cylindrical shell; The inner barrel wall has supercritical fluid to take over, be used to be communicated with the supercritical fluid generator; The urceolus body wall is equipped with constant temperature bath entrance sleeve and discharge connection respectively.

The accent Q pond that described pulse laser is used, it is further characterized in that: described inner barrel is pressure vessel, withstand voltage pressure 〉=10MPa; Described flange and tubular bearing are made an integral body, with focal position, the collimation effect that guarantees condenser lens and collimating lens; Tubular bearing sidewall has the duct.Flange also is the condenser lens bearing simultaneously, regulate two Flange Plane the depth of parallelism, the depth of parallelism of scalable condenser lens interarea then, thus adjust light path.

The accent Q pond that described pulse laser is used, flange, condenser lens, tubular bearing, collimating lens can symmetry be equipped with in the inner barrel two ends; Can be filled with in the described inner barrel closely face outer fluid, promptly near the supercritical fluid of critical point.Can closely face the pressure and temperature of outer fluid by real-time regulated, regulate the threshold value of closely facing the outer fluid stimulated Brillouin scattering, and then regulate the Q value of high energy pulse laser.

Supercritical fluid (SuperCritical Fluid is called for short SCF) is that state is in monophasic fluid (T＞T that critical temperature is above and critical pressure is above _c, p＞p _c).As shown in Figure 2, in supercritical range, the isopycnic of fluid mostly converges on critical point.Near critical point, the small size variation of pressure or temperature can cause the marked change of SCF density.Near the supercritical fluid (or closely facing outer fluid SuperCritical Fluid Near Critical Point, abbreviation SCFNCP) of critical point, its density is between gas and liquid, and density is even, and diffusivity is good.When SCFNCP and laser interaction, it is good except damage threshold height and the recoverability with similar gas, and tensor of polarizability coefficient and high order harmonic component conversion efficiency are than outside the high advantage of gas, also be easy between gas and liquid, significantly regulate because of its density, thereby have the density that changes SCFNCP by control, and then realize optical parameters such as its refractive index, Brillouin scattering threshold value and gain coefficient are given the good character of flexible to temperature and pressure.

By stimulated Brillouin scattering (Stimulated Brillouin Scattering, abbreviation SBS) principle is known, when the laser intensity in incident SBS pond increases to the SBS threshold value, in the SBS pond, can produce back scattering effect with the incident laser phase conjugation, intensity loss reduces suddenly in the resonant cavity at this moment, the Q value increases suddenly, forms Q-switched pulse.By the characteristic of SCFNCP as can be known, change the state of SCFNCP in the pond, then can significantly change the density of SCFNCP and the threshold value of SBS, also just changed the Q value of high energy pulse laser.

Transfer the Q characteristic according to SCF characteristic and SBS, use this accent Q pond, can realize setting in real time or changing the Q value, and can avoid setting the drift of Q value and take the inconvenience that the Q box is transferred in the resonant cavity replacing apart.

Description of drawings

Fig. 1 the present invention transfers Q pool structure schematic diagram;

Fig. 2 supercritical fluid phasor;

Fig. 3 adopts the present invention to transfer the CO of Q ₂The gas laser schematic diagram.

Embodiment

Below in conjunction with the description of drawings embodiments of the present invention.

As shown in Figure 1, it is inside and outside two cylindrical shells that the present invention transfers the basic structure in Q pond, mainly by forming: inner barrel 1, outer cylinder body 2, flange 5, condenser lens 6, collimating lens 4, blind flange 8, and supercritical fluid adapter 11 and constant temperature bath entrance sleeve 3 with the lower part.Metal material adopts stainless steel, and sealing is with elasticity high score subclass material preferably, and lens are with suitable optical material.

Inner barrel has filled SCFNCP, and the chuck between urceolus and the inner core is to be used for to making the circulation constant temperature bath as SCFNCP in the inner barrel in SBS pond.

Before flange 5 welds with inner barrel 1, the depth of parallelism of condenser lens 6 and collimating lens 4 should be checked and guarantee earlier, the correct and collimation effect in focal position be guaranteed.Condenser lens 6 is by sealing 7 and flange 5 sealings; Collimating lens 4 also seals with the tubular bearing that is connected with flange.

It is as follows that supercritical fluid is taken over 11 installation process: leave on inner barrel 1 with supercritical fluid and take over the hole that 11 caliber adapts, weld stiffening plate 9, leave the welding operation hole on outer cylinder body 2.After being set to outer cylinder body 2 on the inner barrel 1, supercritical fluid being taken over 11 be inserted in the perforate of inner barrel 1, stiffening plate 9 and supercritical fluid are taken over 11 weld, play fixing the adapter and sealing; Supercritical fluid adapter 11 is welded with cover plate 10, again cover plate 10 and outer cylinder body 2 are welded, play the effect of poling sealing.The rest may be inferred, and the import and export that can install constant temperature bath are taken over.Welding will be followed national standard or industry standard, and suitably bevel welds with argon shield, and postwelding will be detected a flaw.

Figure 3 shows that the CO that adopts the present invention to transfer Q ₂The gas laser schematic diagram, transfer the Q pond to be loaded in the laser cavity 12, connect by adjustable joint 16, entrance sleeve 3, discharge connection 17 and closely face outer fluid generator 18, in inner barrel 1, charge into SCFNCP, and pressure and temperature is transferred to certain definite value, then the SBS effect has a corresponding threshold.When laser intensity did not reach the SBS threshold value in the inner barrel 1, laser vibrated between window mirror 15, main discharge electrode 14, total reflective mirror 13; When laser intensity increased to the SBS threshold value, the Q value increased suddenly, formed Q-switched pulse.By the characteristic of SCFNCP as can be known, change the state of SCFNCP in the pond, then can significantly change the density of SCFNCP and the threshold value of SBS, also just change the Q value of laser.

Claims

1. accent Q pond that pulse laser is used, has cylindrical shell by the optical frames sealing, it is characterized in that: described cylindrical shell is an inner barrel, its two ends encapsulation flange, two flange center's lead to the hole site all are equipped with condenser lens, and the tubular bearing that is connected with flange is positioned at inner barrel, bearing one end is equipped with collimating lens; Be with outer cylinder body outside the inner barrel, form chuck between the inside and outside cylindrical shell; The inner barrel wall has supercritical fluid to take over, be used to be communicated with the supercritical fluid generator; The urceolus body wall is equipped with constant temperature bath entrance sleeve and discharge connection respectively.

2. the accent Q pond that pulse laser as claimed in claim 1 is used is characterized in that: described inner barrel is pressure vessel, withstand voltage pressure 〉=10MPa; Described flange and tubular bearing are made an integral body, with focal position, the collimation effect that guarantees condenser lens and collimating lens; Tubular bearing sidewall has the duct.

3. the accent Q pond that pulse laser as claimed in claim 1 or 2 is used is characterized in that inner barrel two ends symmetry is equipped with flange, condenser lens, tubular bearing, collimating lens; Described inner core be filled with closely face outer fluid, promptly near the supercritical fluid of critical point.