CN203133390U - Precise wavelength tuning apparatus - Google Patents

Abstract

The utility model relates to a precise wavelength tuning apparatus comprising a beam expander, a grating installation adjusting rack, a blazed grating, a rotating platform, a connecting rod, a linear servo control platform, a first cylindrical pin, and a second cylindrical pin. The provided precise wavelength tuning apparatus with the characteristics of simplified structure and high wavelength tuning precision can be applied to wavelength tuning and wavelength stability controlling of a laser.

Description

Accurate wave length tuning device

Technical field

The utility model relates to a kind of accurate wave length tuning device, and the live width that is mainly used in laser instrument is pressed the Wavelength stabilized control of narrow module and laser instrument.

Background technology

In wavelength tuning, the most frequently used way is blazed grating to be debug frame by grating be fixed on the high precision electrical turntable, by the rotation of servocontrol electrical turntable, realizes the wavelength fine tune.But because the wavelength fine tune requires height to the electrical turntable running accuracy, so often size is big, quality heavy for the electrical turntable that uses in traditional wavelength tuning, complex structure, and cost is very high, has therefore limited its application.

The utility model content

The purpose of this utility model is to provide a kind of accurate wave length tuning device.This device has designs simplification, wavelength tuning precision height, can be applicable to the wavelength tuning of laser instrument and the characteristics of Wavelength stabilized control.

The technical scheme that the utility model solves the problems of the technologies described above is as follows:

A kind of accurate wave length tuning device, it is characterized in that: this device is by beam expander, grating is debug frame, blazed grating, rotation platform, connecting rod, linear servo control platform, first straight pin and second straight pin are formed, described rotation platform is made up of mounting seat and rotatable stage, and the rotatable stage edge designs has threaded hole, described blazed grating is debug frame by grating and is fixed on the rotatable stage, respectively there is a pin-and-hole at the two ends of described connecting rod, the objective table edge designs of described linear servo control platform has a threaded hole, first straight pin and second straight pin are by nut, cylindrical pin and bottom screw rod three parts are formed, first straight pin is inserted described connecting rod one pin-and-hole, and with first straight pin by its bottom screw rod be fixed on the described rotatable stage, first straight pin and connecting rod form first revolute pair, second straight pin is inserted in another pin-and-hole of described connecting rod, and be fixed on second straight pin on the objective table of described linear servo control platform by its bottom screw rod, second straight pin and connecting rod form second revolute pair, described rotation platform, connecting rod, linear servo control platform, first straight pin and second straight pin constitute slider-crank mechanism, the rectilinear motion of described linear servo control platform is converted to the gyration of rotation platform, the rotation of realization blazed grating, the incident angle that light beam incides described blazed grating is changed, realize the wavelength fine tune.

Described beam expander is prism beam-expanded device or the mirror beam expander of looking in the distance, and the rate that the expands control of beam expander is 15 ~ 23.

Described blazed grating is reflective gratings, and grating constant is 1/94.13mm, and blazing angle is 79 °, and the order of diffraction during wavelength 193nm is inferior to be 108.

Described rotation platform is made up of mounting seat and rotatable stage, adopts precision bearing to connect between mounting seat and the rotatable stage, guarantee the stability when rotatable stage rotates, and the rotatable stage edge designs has threaded hole.

The wavelength tuning precision of described device is:

$\mathrm{\&Delta;\&lambda;}=\frac{2d\cos \mathrm{\&alpha;}}{k}(\arccos \frac{\mathrm{\&delta;}{\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="HDA00002714831000011.png"\; state="\{\{state\}\}">l</figure-callout>}}^2}{2r\sqrt{L^2-{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="HDA00002714831000011.png"\; state="\{\{state\}\}">r</figure-callout>}}^2+\mathrm{\&delta;}{l}^2}}-\frac{\mathrm{\&pi;}}{2}+\arctan \frac{\mathrm{\&delta;l}}{\sqrt{L^2-r^2}})$

Wherein: d, α and k are respectively grating constant, blaze of grating angle and the order of diffraction time of blazed grating.δ l is the least displacement amount of linear servo control platform, r be the center of rotation platform to the distance at threaded hole center, L is the distance between two pin-and-hole centers of connecting rod.

Technique effect of the present utility model:

The utility model can be realized the spectral wavelength hair-breadth tuning, compare with classic method, advantage is: by the servocontrol motor is spatially separated with rotation platform, designs simplification, tuning precision raising, weight saving, cost are reduced, can be applicable to wavelength tuning and the Wavelength stabilized control of laser instrument.

Description of drawings

Fig. 1 is the accurate wave length tuning device structural representation of the utility model.

Fig. 2 is the straight pin structural representation.

Fig. 3 is the slider-crank mechanism synoptic diagram.

Embodiment

See also Fig. 1, Fig. 1 is the accurate wave length tuning device structural representation of the utility model.As seen from the figure, the accurate wave length tuning device of the utility model, this device is by beam expander 1, grating is debug frame 2, blazed grating 3, rotation platform 4, connecting rod 5, linear servo control platform 6, first straight pin 7 and second straight pin 8 are formed, described rotation platform 4 is made up of mounting seat 4.1 and rotatable stage 4.2, and rotatable stage 4.2 edge designs have threaded hole 4.2.1, described blazed grating 3 is debug frame 2 by grating and is fixed on the rotatable stage 4.2, respectively there is a pin-and-hole at the two ends of described connecting rod 5, the objective table edge designs of described linear servo control platform 6 has a threaded hole 6.1, see also Fig. 2, first straight pin 7 and second straight pin 8 are by nut, cylindrical pin and bottom screw rod three parts are formed, first straight pin 7 is inserted described connecting rod 5 one pin-and-holes, and with first straight pin 7 by its bottom screw rod be fixed on the described rotatable stage 4.2, first straight pin 7 and connecting rod 5 form first revolute pair, second straight pin 8 is inserted in described connecting rod 5 another pin-and-holes, and be fixed on second straight pin 8 on the objective table of described linear servo control platform 6 by its bottom screw rod, second straight pin 8 and connecting rod 5 form second revolute pair, described rotation platform 4, connecting rod 5, linear servo control platform 6, first straight pin 7 and second straight pin 8 constitute slider-crank mechanism, the rectilinear motion of described linear servo control platform 6 is converted to the gyration of rotation platform 4, realize blazed grating 3 rotations, the incident angle that light beam incides described blazed grating 3 is changed, realize the wavelength fine tune.

Described beam expander 1 is prism beam-expanded device or the mirror beam expander of looking in the distance, and the rate that the expands control of beam expander 1 is 15 ~ 23.

Described blazed grating 3 is reflective gratings, and grating constant is 1/94.13mm, and blazing angle is 79 °, and the order of diffraction during wavelength 193nm is inferior to be 108.

Described rotation platform 4 is made up of mounting seat 4.1 and rotatable stage 4.2, adopt precision bearing to connect between mounting seat 4.1 and the rotatable stage 4.2, guarantee the stability when rotatable stage 4.2 rotates, and rotatable stage 4.2 edge designs there is threaded hole 4.2.1.

The utility model adopts slider-crank mechanism to realize the rotation of blazed grating 3, its structural representation sees also Fig. 2, slider-crank mechanism is a kind of physical construction commonly used, it controls platform 6(slide block with linear servo) to-and-fro movement on straight line is converted into rotation platform 4(crank) rotation, rotation platform 4 can be reduced to crank OQ, rotates around center O; Linear servo control platform 6 is reduced to slide block P, can do back and forth movement along the x axle; Connecting rod 5 is reduced to the line line PQ of regular length, connects slide block and crank.When slide block (linear servo control platform 6) moves to P ' time from the P position, crank (rotation platform 4) is rotated counterclockwise to O ' around center O, and the anglec of rotation is δ θ.The center of note rotation platform 4 is r to the distance at threaded hole 4.2.1 center, and the distance between two pin-and-hole centers of connecting rod 5 is L, ∠ P ' OQ=β, and ∠ POP '=γ, OP ⊥ OQ, OP ⊥ x axle, PP '=δ l according to Pythagorean theorem, can get:

$\mathrm{OP}=\sqrt{L^2-{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="HDA00002714831000011.png"\; state="\{\{state\}\}">r</figure-callout>}}^2},---\left(1\right)$

$O{P}^{\&prime;}=\sqrt{L^2-{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="HDA00002714831000011.png"\; state="\{\{state\}\}">r</figure-callout>}}^2+\mathrm{\&delta;}{\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="HDA00002714831000011.png"\; state="\{\{state\}\}">l</figure-callout>}}^2},---\left(2\right)$

In △ OPP ', OP ⊥ x axle can get:

$\tan \mathrm{\&gamma;}=\frac{P{P}^{\&prime;}}{\mathrm{OP}}=\frac{\mathrm{\&delta;l}}{\sqrt{L^2-{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="HDA00002714831000011.png"\; state="\{\{state\}\}">r</figure-callout>}}^2}},---\left(3\right)$

In △ OP ' Q ', according to the cosine law, can get:

$\cos (\mathrm{\&delta;\&theta;}+\mathrm{\&beta;})=\frac{O{P}^{\&prime;2}+O{Q}^{\&prime;2}-P^{\&prime;}{Q}^{\&prime;2}}{2\&CenterDot;O{P}^{\&prime;}\&CenterDot;O{Q}^{\&prime;}}=\frac{\mathrm{\&delta;}{\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="HDA00002714831000011.png"\; state="\{\{state\}\}">l</figure-callout>}}^2}{2r\sqrt{L^2-{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="HDA00002714831000011.png"\; state="\{\{state\}\}">r</figure-callout>}}^2+\mathrm{\&delta;}{\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="HDA00002714831000011.png"\; state="\{\{state\}\}">l</figure-callout>}}^2}},---\left(4\right)$

In sum, when linear servo control platform 6 moved δ l along the x direction of principal axis, the angle that rotation platform 4 rotates was:

$\mathrm{\&delta;\&theta;}=(\mathrm{\&delta;\&theta;}+\mathrm{\&beta;})-\mathrm{\&beta;}=(\mathrm{\&delta;\&theta;}+\mathrm{\&beta;})-(\frac{\mathrm{\&pi;}}{2}-\mathrm{\&gamma;})$

$=\arccos \frac{\mathrm{\&delta;}{\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="HDA00002714831000011.png"\; state="\{\{state\}\}">l</figure-callout>}}^2}{2r\sqrt{L^2-{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="HDA00002714831000011.png"\; state="\{\{state\}\}">r</figure-callout>}}^2+\mathrm{\&delta;}{l}^2}}-\frac{\mathrm{\&pi;}}{2}+\arctan \frac{\mathrm{\&delta;l}}{\sqrt{L^2-{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="HDA00002714831000011.png"\; state="\{\{state\}\}">r</figure-callout>}}^2}},---\left(5\right)$

When 3 one-tenth Littrows of light beam and blazed grating (Littrow) structure through beam expander 1 output, when namely incident angle equated with blazing angle, grating equation can be written as:

2dsinα＝kλ， (6)

Wherein: d is grating constant, and α is blazed grating 3 blazing angles, and k is that the order of diffraction is inferior.

Grating equation (6) differential is had:

2dcosαΔα＝kΔλ， (7)

Therefore blazed grating 3 corners are identical with rotation platform 4 corners in the utility model, and the wavelength tuning precision is in the time of can being obtained linear servo and controlled the least displacement amount of platform 6 and be δ l by formula (5) and (7):

$\mathrm{\&Delta;\&lambda;}=\frac{2d\cos \mathrm{\&alpha;\&delta;\&theta;}}{k}=\frac{2d\cos \mathrm{\&alpha;}}{k}(\arccos \frac{\mathrm{\&delta;}{\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="HDA00002714831000011.png"\; state="\{\{state\}\}">l</figure-callout>}}^2}{2r\sqrt{L^2-{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="HDA00002714831000011.png"\; state="\{\{state\}\}">r</figure-callout>}}^2+\mathrm{\&delta;}{l}^2}}-\frac{\mathrm{\&pi;}}{2}+\arctan \frac{\mathrm{\&delta;l}}{\sqrt{L^2-r^2}}),---\left(8\right)$

Wherein: blazed grating 3 length d are 1/94.13mm, blazing angle is 79 °, and the order of diffraction when wavelength is 193nm is inferior to be 108, and the precision of linear servo control platform 6 is δ 1=0.5 μ m, distance between two pin-and-hole centers of connecting rod 5 is L=200mm, and the center of rotation platform 4 is to threaded hole

4.2.1 the center apart from r50mm, then the spectral wavelength tuning precision can reach:

In classic method, the angle of rotation precision of the high precision turntable of generally selecting for use is δ θ=0.00008rad, therefore can obtain adopting the wavelength tuning precision of high precision turntable to be:

In sum, compare with classic method, the mentioned wave length tuning device of the utility model is simple in structure, quality is light, the wavelength tuning precision has improved about 30 times, and its cost is lower, can be used widely aspect the tuning and Wavelength stabilized control of laser wavelength.

Claims (5)

1. accurate wave length tuning device, it is characterized in that: this device is by beam expander (1), grating is debug frame (2), blazed grating (3), rotation platform (4), connecting rod (5), linear servo control platform (6), first straight pin (7) and second straight pin (8) are formed, described rotation platform (4) is made up of mounting seat (4.1) and rotatable stage (4.2), and rotatable stage (4.2) edge designs has threaded hole (4.2.1), described blazed grating (3) is debug frame (2) by grating and is fixed on the rotatable stage (4.2), respectively there is a pin-and-hole at the two ends of described connecting rod (5), the objective table edge designs of described linear servo control platform (6) has a threaded hole (6.1), first straight pin (7) and second straight pin (8) are by nut, cylindrical pin and bottom screw rod three parts are formed, first straight pin (7) is inserted described connecting rod (5) one pin-and-holes, and with first straight pin (7) by its bottom screw rod be fixed on the described rotatable stage (4.2), first straight pin (7) and connecting rod (5) form first revolute pair, second straight pin (8) is inserted in another pin-and-hole of described connecting rod (5), and second straight pin (8) is fixed on the objective table of described linear servo control platform (6) by its bottom screw rod, second straight pin (8) and connecting rod (5) form second revolute pair, described rotation platform (4), connecting rod (5), linear servo control platform (6), first straight pin (7) and second straight pin (8) constitute slider-crank mechanism, the rectilinear motion of described linear servo control platform (6) is converted to the gyration of rotation platform (4), realize blazed grating (3) rotation, the incident angle that light beam incides described blazed grating (3) is changed, realize the wavelength fine tune.

2. accurate wave length tuning device according to claim 1 is characterized in that described beam expander (1) is prism beam-expanded device or the mirror beam expander of looking in the distance, and the rate that expands of beam expander (1) is 15 ~ 23.

3. accurate wave length tuning device according to claim 1 is characterized in that described blazed grating (3) is reflective gratings, and grating constant is 1/94.13mm, and blazing angle is 79 °, and the order of diffraction during wavelength 193nm is inferior to be 108.

4. accurate wave length tuning device according to claim 1, it is characterized in that described rotation platform (4) is made up of mounting seat (4.1) and rotatable stage (4.2), adopt precision bearing to connect between mounting seat (4.1) and the rotatable stage (4.2), guarantee the stability when rotatable stage (4.2) rotates, and rotatable stage (4.2) edge designs there is threaded hole (4.2.1).

5. accurate wave length tuning device according to claim 1 is characterized in that the wavelength tuning precision of described device is:

Wherein: d, α and k are respectively grating constant, blaze of grating angle and the order of diffraction time of blazed grating (3), δ l is the least displacement amount of linear servo control platform (6), r be the center of rotation platform (4) to the distance at threaded hole (4.2.1) center, L is the distance between two pin-and-hole centers of connecting rod (5).

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