CN201503386U - Nonlinear coefficient measuring device of irradiation sample - Google Patents

Abstract

The utility model provides a nonlinear coefficient measuring device of an irradiation sample, which is composed of a laser device, a first light filtering sheet, a beam splitting sheet, a sample chamber, a second light filtering sheet, a lens, a first optical power meter, a sample table, a sample table bracket, a sample and a second optical power meter. The sample table and the sample table bracket are respectively arranged in the sample chamber. After being filtered by the light filtering sheets, base frequency light emitted by the laser device is split into two beams by the beam splitting sheet; a small part of the base frequency light is reflected into the second optical power meter, and a large part of the base frequency light is reflected into the sample chamber; after the base frequency light is reflected onto the sample, frequency multiplication wave is stimulated out; after base frequency wave is filtered by the second light filtering sheet, the frequency multiplication wave is focused by the lens and is detected by the first optical power meter; the sample table bracket is rotated to measure the intensity of frequency multiplication light at different angles, so as to obtain a Mark stripe, thereby calculating a nonlinear coefficient and calculating the conversion frequency of harmonic wave according to the reading of the first optical power meter and a third optical power meter. The nonlinear coefficient measuring device can effectively prevent secondary irradiation of the irradiation sample from injuring an experimenter. With the characteristics of compact structure, convenient observing as well as adjusting, safe using and the like, the nonlinear coefficient measuring device is suitable for detecting the irradiation sample.

Description

A kind of irradiation sample nonlinear factor measurement mechanism

Technical field

The utility model relates to a kind of irradiation sample nonlinear factor measurement mechanism, belongs to the material character field of measuring technique of nonlinear optics.

Background technology

The irradiation damage problem is the extremely important problem that military aerospace area research personnel are paid close attention to all the time.As far back as the fifties in last century, people just have been noted that the charged particle that the produces damage problem to material or electronic component in nuclear reaction, particle accelerator and space nature radiation environment, carried out a lot of important research and be applied in the radiation protection of spacecraft.Yet the experiment test for the nonlinear optical material irradiation damage does not almost appear in the newspapers, though the device that much can measure the nonlinear material optical coefficient is arranged at present, but all not being suitable for irradiation sample detects, take place because irradiation sample has secondary radiation after by irradiation, so experimenter's safety and the protection of other optical components all need to consider.In addition, the nonlinear optical properties of irradiation sample very likely can postpone the difference of length and difference with exposure time, therefore also needs this device to measure in real time.

The utility model content

The utility model technical issues that need to address are: overcome the deficiencies in the prior art, a kind of irradiation sample nonlinear factor measurement mechanism is provided, this device can effectively prevent the harm of secondary radiation, and sample observation simultaneously is easy to adjust, helps real-time measurement.

Technical solution of the present utility model is: a kind of irradiation sample nonlinear factor measurement mechanism is made up of laser instrument, first optical filter, beam splitting chip, sample chamber, second optical filter, lens, light power meter, sample stage, sample stage support and light power meter, sample stage, sample stage support all place the sample chamber, sample stage and sample stage support all place the sample chamber, sample places on the sample stage, and sample stage supports by sample holder; The fundamental frequency light that laser instrument sends is divided into two bundles by beam splitting chip after optical filter filtering, the fraction reflection enters first light power meter, and most of transmission enters in the sample chamber, incides and inspires the frequency multiplication ripple on the sample.The existing fundamental component of the light that from sample, transmits, the frequency multiplication composition is also arranged, the frequency multiplication ripple is surveyed to the first light power meter place by lens focus after optical filter filters fundamental wave, and the specimen rotating holder support is measured the frequency doubled light intensity of different angles, obtains specimen Mark (mark) striped.The replacing sample is that the standard quartz crystal repetition said process of non-irradiation records quartz crystal Mark (mark) striped, utilizes the specimen of acquisition and Mark (mark) striped of standard quartz crystal, adopts Mark (mark) the Schlieren method to calculate nonlinear factor.Computing formula is as follows:

${\mathrm{<figure-callout\; id="2"\; label="d\; r"\; filenames="H200920110068XE00011.png"\; state="\{\{state\}\}">d</figure-callout>}}_r^{}={\left[\frac{l_c^q\left(0\right)}{l_c\left(0\right)}\right]}^2\frac{I_m\left(0\right)}{I_m^q\left(0\right)}\frac{f(n_{\mathrm{\&omega;}},{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="H200920110068XE00011.png"\; state="\{\{state\}\}">n</figure-callout>}}_{2\mathrm{\&omega;}})}{f^q(n_{\mathrm{\&omega;}},{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="H200920110068XE00011.png"\; state="\{\{state\}\}">n</figure-callout>}}_{2\mathrm{\&omega;}})}---\left(1\right)$

Wherein

Be the relative value of the nonlinear optical coefficients of testing sample, d is the nonlinear optical coefficients of testing sample,

Nonlinear factor for standard quartz crystal; I _m ^q(0) and I _m(0) is respectively the Maker fringe envelope maximum value of quartz crystal and specimen, n _ω, n _{2 ω}Be fundamental frequency and frequency multiplication refractive index; (1) in the formula,

$f(n_{\mathrm{\&omega;}},{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="H200920110068XE00011.png"\; state="\{\{state\}\}">n</figure-callout>}}_{2\mathrm{\&omega;}})=\frac{{(n_{\mathrm{\&omega;}}+1)}^3{({\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="H200920110068XE00011.png"\; state="\{\{state\}\}">n</figure-callout>}}_{2\mathrm{\&omega;}}+1)}^3(n_{\mathrm{\&omega;}}+{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="H200920110068XE00011.png"\; state="\{\{state\}\}">n</figure-callout>}}_{2\mathrm{\&omega;}})}{{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="H200920110068XE00011.png"\; state="\{\{state\}\}">n</figure-callout>}}_{2\mathrm{\&omega;}}}$

$l_c\left(0\right)=\frac{\mathrm{\&lambda;}}{4|n_{\mathrm{\&omega;}}-{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="H200920110068XE00011.png"\; state="\{\{state\}\}">n</figure-callout>}}_{2\mathrm{\&omega;}}|}$

Reading according to first light power meter and second light power meter calculates harmonic conversion efficient, and computing formula is: η=k (P ₂/ P ₁), wherein k is the reflectivity of beam splitting chip 3, P1, P2 are respectively the reading of first light power meter 9 and second light power meter 13.

Mark's the Schlieren method is the classical way that nonlinear factor calculates, and a lot of documents all have detailed argumentation, can be with reference to pertinent literature.

The utility model compared with prior art has following advantage:

(1) can effectively prevent to be subjected to the harm of irradiation sample secondary radiation, guarantee experiment safety the experimenter.Laboratory sample, sample stage and sample holder all place the sample chamber in this device, and the sample chamber is made by corrosion resistant plate, can effectively stop rays such as α, β, γ.

(2) observation is easy to adjust., can also use except for the transmittance at the circular hole that is provided with on the sample chamber, after can putting into common sample earlier and regulating the position, change irradiation sample again into, so both guarantee experiment safety, convenient again the adjusting as view window.

Description of drawings

Fig. 1 is a structural representation of the present utility model.

Embodiment

As shown in Figure 1, the utility model is by laser instrument 1, first optical filter 2, beam splitting chip 3, sample chamber 5, optical filter 7, lens 8, first light power meter 9, sample stage 10, sample stage support 11, the sample 12 and second light power meter 13 are formed, sample stage 10, sample stage support 11 all places sample chamber 5, sample 12 places on the sample stage 10, sample stage 10 supports by sample holder 11, the fundamental frequency light that laser instrument 1 sends is after optical filter 2 filtering, be divided into two bundles by beam splitting chip 3, the fraction reflection enters second light power meter 13, most of transmission enters in the sample chamber 5, inspire the frequency multiplication ripple after inciding on the sample 12, the existing fundamental component of the light that from sample 12, transmits, the frequency multiplication composition is also arranged, and the frequency multiplication ripple of described transmitted light after second optical filter 7 filters fundamental wave focused on by lens 8, surveyed by first light power meter 9.

When laser instrument 1 when being Nd:YAG pulsed laser, first optical filter 2 for 1064nm optical filter and second optical filter 7, be the nonlinear factor measurement mechanism of typical non linear material phosphoric acid potassium dihydrogen KDP for the 532nm optical filter.

The fundamental light wave of Nd:YAG pulsed laser output is long to be 1064nm, pulse width is 10ns, after 2 filtering of 1064nm second optical filter, be divided into two bundles by beam splitting chip 3, the fraction reflection enters second light power meter 13, most of transmission enters in the sample chamber 5, incides and inspires the frequency multiplication ripple on the KDP sample 12.The existing fundamental component of the light that transmits from sample 12 also has the frequency multiplication composition, and this transmitted light is focused on first light power meter, 9 places through 532nm second optical filter 7 filtered frequency multiplication ripples by lens 8 and surveys.Regulate sample stage support 11 sample 12 is horizontally rotated, measure the frequency doubled light intensity of different angles, obtain Mark (mark) striped.Changing sample 12 is the standard quartz crystal of non-irradiation, repeats said process and records quartz crystal Mark (mark) striped.Utilize the KDP of acquisition and Mark (mark) striped of quartz crystal, adopt Mark (mark) the Schlieren method to calculate nonlinear factor.Computing formula is as follows: (1);

Wherein

Be the relative value of the nonlinear optical coefficients of testing sample, d is the nonlinear optical coefficients of testing sample, Nonlinear factor for standard quartz crystal; I _m ^q(0) and I _m(0) is respectively the Maker fringe envelope maximum value of quartz crystal and specimen, n _ω, n _{2 ω}Be fundamental frequency and frequency multiplication refractive index; (1) in the formula,

$f(n_{\mathrm{\&omega;}},{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="H200920110068XE00011.png"\; state="\{\{state\}\}">n</figure-callout>}}_{2\mathrm{\&omega;}})=\frac{{(n_{\mathrm{\&omega;}}+1)}^3{({\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="H200920110068XE00011.png"\; state="\{\{state\}\}">n</figure-callout>}}_{2\mathrm{\&omega;}}+1)}^3(n_{\mathrm{\&omega;}}+{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="H200920110068XE00011.png"\; state="\{\{state\}\}">n</figure-callout>}}_{2\mathrm{\&omega;}})}{{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="H200920110068XE00011.png"\; state="\{\{state\}\}">n</figure-callout>}}_{2\mathrm{\&omega;}}}$

$l_c\left(0\right)=\frac{\mathrm{\&lambda;}}{4|n_{\mathrm{\&omega;}}-{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="H200920110068XE00011.png"\; state="\{\{state\}\}">n</figure-callout>}}_{2\mathrm{\&omega;}}|}$

Reading according to first light power meter 9 and second light power meter 13 calculates harmonic conversion efficient, and computing formula is: η=k (P ₂/ P ₁), wherein k is the reflectivity of beam splitting chip 3, P1, P2 are respectively the reading of first light power meter 9 and second light power meter 13.

Sample chamber 5 in the utility model is a square structure, and material is the thick corrosion resistant plate of 5mm～10mm, about two walls one circular hole is arranged.Circularhole diameter 5～10cm, embedded ordinary optical glass.Beam splitting chip 3 is the strong transmission beam splitting chip of weak reflection, and reflectivity is less than 5%, and transmissivity is greater than 95%.Sample stage support 11 is four-dimensional adjusting bracket, can the three-dimensional regulation sample stage make the testing sample horizontal positioned, can also rotate around Z-axis simultaneously, and angular resolution is 1 ° or higher.

Claims (4)

1. an irradiation sample nonlinear factor measurement mechanism is characterized in that: be made up of laser instrument (1), first optical filter (2), beam splitting chip (3), sample chamber (5), second optical filter (7), lens (8), first light power meter (9), sample stage (10), sample stage support (11), sample (12) and second light power meter (13); Sample stage (10) and sample stage support (11) all place sample chamber (5), and sample (12) places on the sample stage (10), and sample stage (10) supports by sample holder (11); The fundamental frequency light that laser instrument (1) sends is after first optical filter (2) filtering, be divided into two bundles by beam splitting chip (3), the fraction reflection enters second light power meter (13), most of transmission enters in the sample chamber (5), incide and inspire the frequency multiplication ripple after sample (12) is gone up, the existing fundamental component of light that from sample (12), transmits, the frequency multiplication composition is also arranged, the frequency multiplication ripple of the light of described transmission from sample (12) after second optical filter (7) filters fundamental wave focused on by lens (8), survey by first light power meter (9), specimen rotating holder support (11) is measured the frequency doubled light intensity of different angles, obtain Mark (mark) striped, calculate nonlinear factor, according to the reading calculating harmonic conversion efficient of first light power meter (9) and second light power meter (13); Described nonlinear factor computing formula is: Wherein Be the relative value of the nonlinear optical coefficients of testing sample, d is the nonlinear optical coefficients of testing sample,

Nonlinear factor for standard quartz crystal; I _m ^q(0) and I _m(0) is respectively the Maker fringe envelope maximum value of quartz crystal and specimen, n _ω, n _{2 ω}Be fundamental frequency and frequency multiplication refractive index;

Harmonic conversion efficiency calculation formula is: η=k (P ₂/ P ₁), wherein k is the reflectivity of beam splitting chip 3, P1, P2 are respectively the reading of first light power meter 9 and second light power meter 13.

2. the nonlinear factor measurement mechanism of irradiation sample according to claim 1 is characterized in that: described beam splitting chip (3) for reflectivity less than 5%, transmissivity is greater than 95% beam splitting chip.

3. the nonlinear factor measurement mechanism of irradiation sample according to claim 1 is characterized in that: described sample chamber (5) are square structure, and material is the thick corrosion resistant plate of 5mm～10mm, about two walls one circular hole is respectively arranged, the diameter 5～10cm of circular hole.

4. the nonlinear factor measurement mechanism of irradiation sample according to claim 1, it is characterized in that: described sample stage support (11) is four-dimensional adjusting bracket.

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