CN104483098B - Crystal match angle off-line measurement error real-time correcting method - Google Patents

Abstract

The invention discloses a kind of crystal match angle off-line measurement error real-time correcting method, using incident laser drift angle during Laser Autocollimator monitoring crystal match angular measurement, be more than predetermined threshold value 0.4 if laser drift angle " if cast out the angle and float excessive measurement data; application autocollimator monitors the anglec of rotation deviation that crystal to be measured during crystal measurement occurs, and the anglec of rotation deviation wherein retained is substituted into being calculated into matching angle.Its remarkable result is：Light path standard skew in measurement process and the drift of optics angle are corrected in real time by autocollimator, and being corrected to dynamic error during crystal match angular measurement, the Static error correction situation changed over just for benchmark, the accuracy of crystal match angular measurement is ensure that, the dynamic measurement error in heavy caliber crystal off-line measurement system can be at utmost eliminated.

Description

Crystal match angle off-line measurement error real-time correcting method

Technical field

It is that a kind of crystal match angle off-line measurement error is real specifically the present invention relates to optical engineering technical field When modification method.

Background technology

At present, in solid high power laser system, due to KDP crystal best match angle with the optical axis of crystal cutting work The factors such as skill, the face shape of crystal and refractive index inhomogeneity are relevant, so as to cause accurate, quick measurement to turn into current optimal Hot issue in supporting role's test.

There are two errors, as crystal moving displacement always in the off-line system measurement process of heavy caliber crystal match angle Error, incident laser angle drift measurement error, the presence of this two errors have a strong impact on the accuracy of measurement result.

However, the domestic amendment on heavy caliber crystal match angle off-line measurement error predominantly stays in laser alignment, crystalline substance In terms of the Static implicit methods such as honorable shape influence factor amendment, but on moving displacement error, the real-time angle drift of laser in measurement process Etc. influence factor but without related effective treating method.

The content of the invention

In view of the shortcomings of the prior art, repaiied in real time it is an object of the invention to provide a kind of crystal match angle off-line measurement error Correction method, this method can eliminate the dynamic measurement errors such as the real-time angle drift of moving displacement error, laser in measurement process to crystal The influence of matching angle off-line measurement.

To reach above-mentioned purpose, a kind of crystal match angle off-line measurement error real-time correcting method of present invention statement, its pass Key is to follow the steps below：

Step 1：During crystal best match angular measurement, each measurement point is monitored at different angles using crystal autocollimator The lower Crystal Rotation angular deviation x to be measured occurred of degree_i', wherein i is measurement sequence number, i=1~n；

Step 2：The laser angular for measuring incident beam using Laser Autocollimator floats θ '_i, and with predetermined threshold value θ₀Compare, if θ’_iMore than θ₀, then the Crystal Rotation angular deviation x to be measured that this measurement is obtained is deleted_i' with the motor position of Crystal-support mechanism x_iIf, θ '_iLess than θ₀, then the Crystal Rotation angular deviation x to be measured that this measurement is obtained is retained_i', the motor of Crystal-support mechanism Position x_iAnd and the corresponding energy meter 2 in the position and the reading of energy meter 1 ratio y_i, and enter step 3；

Step 3：The anglec of rotation deviation x occurred during by the Crystal Rotation to be measured of reservation_i' with the motor of Crystal-support mechanism Position x_iAccording to the fit curve equation P at crystal best match angle_m(x)=a₀+a₁x+…a_mx^mIt is fitted, obtains Crystal-support The ratio y of the corresponding energy meter 2 of the real electrical machinery position x of mechanism and the position and the reading of energy meter 1

The fit curve equation at crystal best match angle is：

P_m(x)=a₀+a₁x+…a_mx^m

Then each discrete point (x_i+x_i',y_i) point (x corresponding with matched curve_i+x_i',P_m(x_i+x_i')) difference square With for：

Only try to achieve so that above functional value reaches minimum, matched curve P_m(x_i) per point function value just closest to actual value. Make above functional value minimum, need to superior function respectively to a₀, a₁..., a_mCarry out derivation：

I.e.：

Because of P_m(x) highest number of times is m, and coefficient of correspondence is a_m, therefore m+1 equation group can be arranged：

A just can be solved according to above equation group₀, a₁..., a_m, so as to draw fit curve equation P_m(x_i), then to P_m (x_i) derivation is carried out, using measured data scope as domain of definition (x₁+x₁',x_i+x_i') in ask its maximum, the corresponding x of maximum It is worth the real electrical machinery position for Crystal-support mechanism, the crystal best match Angle Position as after error correction.As more entering one The technical scheme of step, the laser angular drift predetermined threshold value θ₀Value is 0.4 ".

Incident laser drift angle in this method application Laser Autocollimator monitoring measurement process, if laser drift angle More than predetermined threshold value 0.4 " then cast out the angle and float excessive measurement data, using to be measured during autocollimator monitoring crystal measurement The anglec of rotation deviation that crystal occurs, the anglec of rotation deviation wherein retained is substituted into being calculated into matching angle, can be with maximum journey Degree eliminates the dynamic measurement error in heavy caliber crystal off-line measurement system.

The present invention remarkable result be：Light path standard skew in measurement process and the drift of optics angle are carried out by autocollimator Amendment, and being corrected to dynamic error during crystal match angular measurement in real time, changes over just for benchmark Static error correction situation, it is ensured that the accuracy of crystal match angular measurement, can at utmost eliminate heavy caliber crystal from Dynamic measurement error in line measuring system.

Brief description of the drawings

Fig. 1 is the light path schematic diagram of the present invention；

Fig. 2 is flow chart of the method for the present invention.

Embodiment

The embodiment and operation principle to the present invention are described in further detail below in conjunction with the accompanying drawings.

Crystal match angle off-line measurement system of the present invention is as shown in figure 1, the system includes laser, spectroscope 1st, spectroscope 2, periscope 1, periscope 2, heavy caliber standard mirror and crystal to be measured, laser is sent from the laser, by institute State spectroscope 1 and incident laser is divided into two beams：A branch of to incide on energy meter 1, another beam is incided by the periscope 1 to be treated Survey on the periscope 2 after crystal, incident beam is divided into two beams by the spectroscope 2 after the reflection of periscope 2：It is wherein a branch of Incide energy meter 2.

Wherein, the laser is 1053nm lasers, model PL3143A-2-DPSS, and main performance index parameter is Output of laser wavelength is 1053nm；Pulsewidth is 50ps；Repetition rate is 2Hz；Laser energy is 50mJ；Energy stability is 1.5%；The angle of divergence is 0.5mrad；The Laser Autocollimator uses infrared laser high precision photoelectric digital display autocollimator, and it is adopted Use double light source designs：It is including the 635nm visible reds light source for slightly collimating and infrared sharp for the 1053nm of Accurate collimation Radiant.It not only can carry out auto-collimation or angle measurement using itself light source, be also subjected to external infrared laser be collimated or Angle measurement, with automatic data collection and preservation function, it is easy to accomplish intelligentized control method.Its main performance index parameter：Auto-collimation Precision is superior to 1 with angle measurement accuracy ", measurable angle range about 1200 ".

The crystal autocollimator uses Collapex AC300 type digital display photoelectric autocollimators, and the collimator has data Automatic data collection and preservation function, it is easy to accomplish intelligentized control method.Its main performance index parameter：Auto-collimation precision is better than 1 ", survey Angular accuracy is better than 0.3 ", measurable angle range about 1200 ".

As shown in Fig. 2 invention have been described a kind of crystal match angle off-line measurement error real-time correcting method, according to following Step is carried out：

Step 1：The energy meter reading of energy meter 1 and 2 is acquired, Different matching horn shape state on crystal to be measured is completed When energy change value measurement, order measure discrete point coordinate be (x_i+x’_i,y_i), and surveyed using the monitoring of crystal autocollimator The Crystal Rotation angular deviation x to be measured that amount point occurs under different angles_i', wherein, xi is the motor position of Crystal-support mechanism Put, i is measurement sequence number, y_iFor the ratio of crystal energy meter 2 and the reading of energy meter 1 at Different matching angle, i=1~n；

Step 2：The laser angular for measuring incident beam using Laser Autocollimator floats θ '_i, and with predetermined threshold value θ₀Compare, if θ’_iMore than θ₀, then the Crystal Rotation angular deviation x to be measured that this measurement is obtained is deleted_i' with the motor position of Crystal-support mechanism x_iIf, θ '_iLess than θ₀, then the Crystal Rotation angular deviation x to be measured that this measurement is obtained is retained_i' with the motor of Crystal-support mechanism Position x_iAnd and the corresponding energy meter 2 in the position and the reading of energy meter 1 ratio y_i, and enter step 3；Described in this example θ₀Value is 0.4 "；

Step 3：The anglec of rotation deviation x occurred during by the Crystal Rotation to be measured of reservation_i' with the motor of Crystal-support mechanism Position x_iAccording to the fit curve equation P at crystal best match angle_m(x)=a₀+a₁x+…a_mx^mIt is fitted, obtains Crystal-support The ratio y of the corresponding energy meter 2 of the real electrical machinery position x of mechanism and the position and the reading of energy meter 1.Therefore, dynamic is eliminated Crystal best match angle computational methods after error are as follows：

The fit curve equation at known crystal best match angle is：

P_m(x)=a₀+a₁x+…a_mx^m

Then each discrete point (x_i+x_i',y_i) point (x corresponding with matched curve_i+x_i',P_m(x_i+x_i')) difference square With for：

Only try to achieve so that above functional value reaches minimum, matched curve P_m(x_i) per point function value just closest to actual value. Make above functional value minimum, need to superior function respectively to a₀, a₁..., a_mCarry out derivation：

I.e.：

Because of P_m(x) highest number of times is m, and coefficient of correspondence is a_m, therefore m+1 equation group can be arranged：

A just can be solved according to above equation group₀, a₁..., a_m, so as to draw fit curve equation P_m(x_i), then to P_m (x_i) derivation is carried out, using measured data scope as domain of definition (x₁+x₁',x_i+x_i') in ask its maximum, the corresponding x of maximum Value is the crystal best match Angle Position after error correction.

Claims (2)

1. a kind of crystal match angle off-line measurement error real-time correcting method, it is characterised in that follow the steps below：

Step 1：During crystal best match angular measurement, each measurement point is monitored under different angles using crystal autocollimator The Crystal Rotation angular deviation x to be measured occurred_i', wherein i is measurement sequence number, i=1~n；

Step 2：The laser angular for measuring incident beam using Laser Autocollimator floats θ '_i, and with predetermined threshold value θ₀Compare, if θ '_iGreatly In θ₀, then the Crystal Rotation angular deviation x to be measured that this measurement is obtained is deleted_i' with the motor position x of Crystal-support mechanism_iIf, θ’_iLess than θ₀, then the Crystal Rotation angular deviation x to be measured that this measurement is obtained is retained_i', the motor position x of Crystal-support mechanism_i And the ratio y of the corresponding energy meter 2 in the position and the reading of energy meter 1_i, and enter step 3；

Step 3：The anglec of rotation deviation x occurred during by the Crystal Rotation to be measured of reservation_i' with the motor position of Crystal-support mechanism x_iAccording to the fit curve equation P at crystal best match angle_m(x)=a₀+a₁x+…a_mx^mIt is fitted, obtains Crystal-support mechanism The corresponding energy meter 2 of real electrical machinery position x and the position and the reading of energy meter 1 ratio y

The fit curve equation at crystal best match angle is：

P_m(x)=a₀+a₁x+…a_mx^m

Then each discrete point (x_i+x_i',y_i) point (x corresponding with matched curve_i+x_i',P_m(x_i+x_i')) difference quadratic sum For：

$F(a_0,a_1,...,a_m)=\underset{i=1}{\overset{n}{\Σ}}{\mathrm{\σ}}^2=\underset{i=1}{\overset{n}{\Σ}}{\[y_i-P_m(x_i+{x_i}^{\′})\]}^2$

Only try to achieve so that above functional value reaches minimum, matched curve P_m(x_i) per point function value just closest to actual value, to make Above functional value is minimum, need to superior function respectively to a₀, a₁..., a_mCarry out derivation：

I.e.：

Because of P_m(x) highest number of times is m, and coefficient of correspondence is a_m, therefore m+1 equation group can be arranged：

$\left\{\begin{array}{c}{\mathrm{na}}_0+a_1\underset{i=1}{\overset{n}{\Σ}}(x_i+{x_i}^{\′})+\mathrm{...}+a_m\underset{i=1}{\overset{n}{\Σ}}{(x_i+{x_i}^{\′})}^m=\underset{i=1}{\overset{n}{\Σ}}{y}_i\\ a_0\underset{i=1}{\overset{n}{\Σ}}(x_i+{x_i}^{\′})+a_1\underset{i=1}{\overset{n}{\Σ}}{(x_i+{x_i}^{\′})}^2+\mathrm{...}+a_m\mathrm{\Σ}{(x_i+{x_i}^{\′})}^{m+1}=\underset{i=1}{\overset{n}{\Σ}}{y}_i(x_i+{x_i}^{\′})\\ \mathrm{......................................................}\\ a_0\underset{i=1}{\overset{n}{\Σ}}{(x_i+{x_i}^{\′})}^m+a_1\underset{i=1}{\overset{n}{\Σ}}{(x_i+{x_i}^{\′})}^{m+1}+\mathrm{...}+a_m\underset{i=1}{\overset{n}{\Σ}}{(x_i+{x_i}^{\′})}^{2m}=\underset{i=1}{\overset{n}{\Σ}}{y}_i{(x_i+{x_i}^{\′})}^m\end{array}\right.$

A just can be solved according to above equation group₀, a₁..., a_m, so as to draw fit curve equation P_m(x_i), then to P_m(x_i) Derivation is carried out, using measured data scope as domain of definition (x₁+x₁', x_i+x_i') in seek its maximum, the corresponding x values of maximum are The real electrical machinery position of Crystal-support mechanism, the crystal best match Angle Position as after error correction.

2. off-line measurement error real-time correcting method in crystal match angle according to claim 1, it is characterised in that：Step 2 Described in laser angular float predetermined threshold value θ₀Value is 0.4 ".