CN103604776A - Phase delay measuring apparatus and method - Google Patents

Abstract

The invention provides a phase delay measuring apparatus and a phase delay measuring method. The apparatus comprises a beam splitting meter, a first detector, a second detector, a first rotary table and a Glan-Taylor prism. The first rotary table is used for bearing a to-be-measured sample and enabling the sample to rotate along a horizontal axis; monochromatic polarized light undergoes beam splitting by the beam splitting meter, then one light beam I irradiates onto the first detector, and the other light beam II irradiates onto the Glan-Taylor prism and then irradiates onto the second detector after passing through the Glan-Taylor prism. The phase delay measuring apparatus and the phase delay measuring method provided by the invention have measurement accuracy independent on the characteristics of a material and can greatly improve measurement precision.

Description

A kind of phase-delay measurement device and method

Technical field

The present invention relates to field of measuring technique, relate in particular to a kind of phase-delay measurement device and method.

Background technology

Along with the fast development of material subject, the measurement of optical material phase-delay characteristic has been proposed to very high requirement.

The measuring method of current known phase delay mainly contains: Resonant-cavity Method, phase compensation method, spectral scan mensuration, polarization modulation method, optical heterodyne method, Moire deflectometry, penalty method, double light path phase-comparison method and photon flux method etc.But the measuring accuracy of these methods is low, be difficult to satisfy the demands.

Summary of the invention

The invention provides a kind of phase-delay measurement device and method, the accuracy of measurement can be independently and material self-characteristic, and can greatly improve the precision of measurement.

The invention provides a kind of phase-delay measurement device, comprise monochromatic polarized light source, beam splitting meter, the first detector, the second detector, the first turntable, Glan-Taylor prism, described the first turntable is used for carrying detected sample and rotates along transverse axis, and monochromatic polarized light is after beam splitting score light, wherein a branch of light beam one is irradiated to the first detector, another light beams two is irradiated on Glan-Taylor prism through detected sample, and after Glan-Taylor prism, is being irradiated on the second detector.

Preferably, described monochromatic polarized light source comprises: super continuum light spectrum light source, beam splitting system, diaphragm;

Wherein, described beam splitting system meets following condition: the extinction ratio through the light beam of described beam splitting system outgoing is greater than 55dB.

Preferably, this device also comprises: constant temperature oven, during measurement described in detected sample be positioned at described constant temperature oven.

Preferably, this device also comprises: light trapping, and for absorbing the light beam through the first detector and/or the reflection of the second detector.

The present invention also provides a kind of method of utilizing device described in above-mentioned any one to realize phase-delay measurement, comprising:

The light beam two of take rotates described detected sample according to default step-length as axle, and records the electric current I that described the first detector detects ₁the electric current I detecting with described the second detector ₂;

According to described electric current I ₁and I ₂calculate the phase-delay value of described detected sample.

Preferably, while comprising constant temperature oven in described device, describedly take light beam two before axle rotates described detected sample according to default step-length, described method also comprises: described constant temperature oven is adjusted to described default temperature.

Preferably, described according to described electric current I ₁and I ₂the phase-delay value that calculates described detected sample, is specially: utilize following formula to calculate the phase-delay value σ of detected sample:

$\mathrm{\&delta;}=2\arcsin \sqrt{(I_{\max }-I_{\min })/(I_{\max }+I_{\min }{\mathrm{<figure-callout\; id="2"\; label="tan"\; filenames="HDA0000426267190000011.png"\; state="\{\{state\}\}">tan</figure-callout>}}^2{\mathrm{\&theta;}}_2)};$

I=I wherein ₁/ I ₂, I _maxand I _maxbe respectively maximum occurrences and the minimum value of I, θ be described Glan-Taylor prism rise folk prescription to and the light path plane of polarization of described monochromatic polarized light between angle.

A kind of phase-delay measurement device provided by the invention comprises: beam splitting meter, the first detector, the second detector, the first turntable, Glan-Taylor prism, described the first turntable is used for carrying detected sample and rotates along transverse axis, and monochromatic polarized light is after beam splitting score light, wherein a branch of light beam one is irradiated to the first detector, another light beams two is irradiated on Glan-Taylor prism through detected sample, and after Glan-Taylor prism, is being irradiated on the second detector.Phase-delay measurement device and method provided by the invention, the accuracy of its measurement can be independently and material self-characteristic, and can greatly improve the precision of measurement.

Accompanying drawing explanation

Fig. 1 is the structural representation of a kind of phase-delay measurement device provided by the invention;

Fig. 2 is the method flow diagram of a kind of phase-delay measurement provided by the invention.

Embodiment

Below in conjunction with drawings and Examples, the specific embodiment of the present invention is further described.Following examples are only for technical scheme of the present invention is more clearly described, and can not limit the scope of the invention with this.

The embodiment of the present invention one provides a kind of phase-delay measurement device, as shown in Figure 1, comprising:

Monochromatic polarized light source, beam splitting meter 1, the first detector 2, the second detector 3, the first turntable 4, Glan-Taylor prism 5, the first turntable 4 rotates along transverse axis for carrying detected sample 6, and monochromatic polarized light is after beam splitting score light, wherein a branch of light beam one is irradiated to the first detector 2, another light beams two is irradiated on Glan-Taylor prism 5 through detected sample 6, and after Glan-Taylor prism 5, is being irradiated on the second detector 3.

Use phase-delay measurement device provided by the invention, the accuracy of measurement can be independently and material self-characteristic, and can greatly improve the precision of measurement.

What preferably, this light-source system can be in following two kinds of modes is a kind of:

Mode one, as shown in Figure 1, this monochrome polarized light source system comprises: super continuum light spectrum light source 7, beam splitting system 8, diaphragm 9, and the polarizer, the optical radiation that super continuum light spectrum light source 7 sends is divided into needed polarization monochromatic light through beam splitting system 8, and monochromatic light becomes the circular light spot of collimation after diaphragm 9, circular light becomes polarized light after the polarizer, and polarized light is divided into two bundles after beam splitting meter 1.Wherein the above-mentioned polarizer can be set to light beam the device of High Extinction Ratio polarized light for Glan-Taylor prism or other.

Mode two, can provide the LASER Light Source of polarized light.

Preferably, one or several in can be in the following ways further improve precision of measuring:

A), select suitable beam splitting system 8 to make to be greater than 55dB through the extinction ratio of the light beam of beam splitting system 8 outgoing, or when light-source system that light-source system provides for above-mentioned mode one, in light path, before diaphragm 3 positions, increase the element that High Extinction Ratio surpasses 55dB.

B), State selective measurements precision must reach or be better than the current measurement system (comprising detector and other additional devices) that 5 half, dynamic range surpass 8 orders of magnitude.

C), the minimum step of the first turntable is lower than 0.001 °.

D), a constant temperature oven 10 is as shown in Figure 1 set in device, during measurement described in detected sample be positioned at constant temperature oven 10.

E), light trapping 11 is as shown in Figure 1 set, this light trapping is for absorbing the light beam through the first detector and/or the reflection of the second detector.

Preferably, Glan-Taylor prism 5 is installed on the second turntable 12, for regulating and the fixing angle of Glan-Taylor prism 5.

Design based on identical, the present invention also provides a kind of method of phase-delay measurement, the phase delaying device that the method utilizes above-mentioned arbitrary embodiment to provide is measured the phase-delay characteristic of detected sample, and its idiographic flow can comprise each step as shown in Figure 2:

Step 201, the light beam two of take rotates described detected sample according to default step-length as axle, and records the electric current I that described the first detector detects ₁the electric current I detecting with described the second detector ₂.Light beam two, for what obtain through beam splitting meter 1, is radiated at the light beam on detected sample 6.

During actual measurement, detected sample 6 should be arranged in the first turntable 4, and minute adjustment position, the reflected light of sample surfaces is overlapped substantially with incident light.From 0 ° (angle value corresponding to initial position thought to 0 °), with 0.01 ° of step-length, forward 6 to 90 ° of detected samples to afterwards, and record the system output reading under each angle state.

Step 202, according to described electric current I ₁and I ₂calculate the phase-delay value of described detected sample.

Preferably, while including constant temperature oven 10 in device, before above-mentioned step 201, also comprise: described constant temperature oven is adjusted to described default temperature.In practical application, the temperature stability of constant temperature oven 10 should be better than 0.02 ℃/24 hours.Until constant temperature oven 12, reach after target temperature, at least need to wait for after 1 hour, can carry out the measurement of material phase delay.

Preferably, above-mentioned step 202 comprises:

Utilize following formula to calculate the phase-delay value σ of detected sample:

$\mathrm{\&delta;}=2\arcsin \sqrt{(I_{\max }-I_{\min })/(I_{\max }+I_{\min }{\mathrm{<figure-callout\; id="2"\; label="tan"\; filenames="HDA0000426267190000011.png"\; state="\{\{state\}\}">tan</figure-callout>}}^2{\mathrm{\&theta;}}_2)};$

I=I wherein ₁/ I ₂, I ₁be the current value of the first detector record, I ₂be the current value of the first detector record, I _maxand I _maxbe respectively maximum occurrences and the minimum value of I, θ is the angle between the light path plane of polarization of Glan-Taylor prism 5 and monochromatic polarized light.

Through test, find, phase-delay measurement device provided by the invention, goes within the scope of 400nm-2000nm, the high-acruracy survey of the phase delay of any materials, and irrelevant with the major axes orientation of material self.

The above is only the preferred embodiment of the present invention; it should be pointed out that for those skilled in the art, do not departing under the prerequisite of the technology of the present invention principle; can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.

Claims (7)

1. a phase-delay measurement device, it is characterized in that, comprise monochromatic polarized light source, beam splitting meter, the first detector, the second detector, the first turntable, Glan-Taylor prism, described the first turntable is used for carrying detected sample and rotates along transverse axis, and monochromatic polarized light is after beam splitting score light, wherein a branch of light beam one is irradiated to the first detector, and another light beams two is irradiated on Glan-Taylor prism through detected sample, and after Glan-Taylor prism, is being irradiated on the second detector.

2. device as claimed in claim 1, is characterized in that, described monochromatic polarized light source comprises: super continuum light spectrum light source, beam splitting system, diaphragm;

Wherein, described beam splitting system meets following condition: the extinction ratio through the light beam of described beam splitting system outgoing is greater than 55dB.

3. device as claimed in claim 1, also comprises: constant temperature oven, during measurement described in detected sample be positioned at described constant temperature oven.

4. device as claimed in claim 1, is characterized in that, also comprises: light trapping, and for absorbing the light beam through the first detector and/or the reflection of the second detector.

5. the device of utilization as described in claim 1-4 any one realized a method for phase-delay measurement, it is characterized in that, comprising:

The light beam two of take rotates described detected sample according to default step-length as axle, and records the electric current I that described the first detector detects ₁the electric current I detecting with described the second detector ₂;

According to described electric current I ₁and I ₂calculate the phase-delay value of described detected sample.

6. method as claimed in claim 5, it is characterized in that, while comprising constant temperature oven in described device, describedly take light beam two before axle rotates described detected sample according to default step-length, described method also comprises: described constant temperature oven is adjusted to described default temperature.

7. method as claimed in claim 6, is characterized in that, described according to described electric current I ₁and I ₂the phase-delay value that calculates described detected sample, is specially: utilize following formula to calculate the phase-delay value σ of detected sample:

$\mathrm{\&delta;}=2\arcsin \sqrt{(I_{\max }-I_{\min })/(I_{\max }+I_{\min }{\tan }^2{\mathrm{\&theta;}}_2)};$

I=I wherein ₁/ I ₂, I _maxand I _maxbe respectively maximum occurrences and the minimum value of I, θ be described Glan-Taylor prism rise folk prescription to and the light path plane of polarization of described monochromatic polarized light between angle.

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