CN107631694B - Method for measuring thickness of optical component - Google Patents
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Abstract
The invention discloses a method for measuring the thickness of an optical component, wherein a device for measuring the thickness of the optical component comprises a wide-spectrum light source, an electro-optic modulator and a calculator, the output end of the wide-spectrum light source is connected with a first optical fiber coupler, one output end of the first optical fiber coupler is connected with an optical component mounting seat to be measured, the output light of the optical component mounting seat to be measured and the output light of the first optical fiber coupler are combined through a second optical fiber coupler, the first optical fiber coupler, the optical component mounting seat to be measured and the second optical fiber coupler form a Mach-Zehnder interferometer, the output end of the Mach-Zehnder interferometer is connected with the electro-optic modulator, and a modulation signal output by the electro-optic modulator is incident on a high-speed photoelectric detector after passing through a dispersion; the invention has the advantages of micron-order measurement sensitivity and good application prospect.
Description
Technical Field
The invention relates to a measuring method, in particular to a measuring method for the thickness of an optical component.
Background
The thickness is one of the important parameters of optical components, especially the optical components with birefringence characteristics, and the thickness directly determines the application effect of the optical components in the aspects of optical wave plates, optical retardation, laser measurement and the like. The thickness of an optical component is a basic physical quantity characterizing the optical material of a substance, and this parameter is an important condition for determining the synthesis, manufacture and application of the substance in various fields.
At present, the method for measuring the thickness of the optical component mainly comprises a physical measurement method, an optical interference method, a magnetron sputtering radio frequency method and the like, and the methods often have the defect of low thickness measurement sensitivity of a measurement system and cannot meet the requirement of accurate measurement, so the invention provides the method for measuring the thickness of the optical component based on the microwave photon technology to solve the problems.
Disclosure of Invention
The invention aims to solve the technical problem of overcoming the defect of low measurement sensitivity of the conventional thickness measuring device and provides a device for measuring the thickness of an optical component, thereby solving the problem.
In order to solve the technical problems, the invention provides the following technical scheme:
the invention relates to a device for measuring the thickness of an optical component, which comprises a wide-spectrum light source, an electro-optic modulator and a calculator, wherein the output end of the wide-spectrum light source is connected with a first optical fiber coupler, one output end of the first optical fiber coupler is connected with an optical device mounting seat to be measured, the output light of the optical device mounting seat to be measured and the output light of the first optical fiber coupler are combined through a second optical fiber coupler, the first optical fiber coupler, the optical device mounting seat to be measured and the second optical fiber coupler form a Mach-Zehnder interferometer, the output end of the Mach-Zehnder interferometer is connected with the electro-optic modulator, a modulation signal output by the electro-optic modulator is subjected to optical fiber dispersion and then is incident on a high-speed photoelectric detector, the high-speed photoelectric detector converts an optical signal into a microwave signal and amplifies the microwave signal through low-noise amplifier, the output end of the low-noise amplifier is connected with a microwave power divider, and simultaneously, inputting the other part of microwave signals into a frequency spectrograph, wherein the tail end of the frequency spectrograph is connected with a computer.
As a preferred technical scheme of the invention, the electro-optical modulator, the dispersion optical fiber, the high-speed photoelectric detector, the low-noise amplifier and the microwave power divider form an optoelectronic oscillator loop, the input end of the optoelectronic oscillator loop is connected with the output end of the Mach-Zehnder interferometer, and the sinusoidal comb spectrum generated at the output end of the Mach-Zehnder interferometer can be injected into the optoelectronic oscillator loop and generates a microwave signal through the optoelectronic oscillator loop.
As a preferred technical scheme of the invention, after a wide-spectrum light source passes through a Mach-Zehnder interferometer, when the optical path difference of two arms of the interferometer is within the coherent range of the light source, interference fringes are generated at the output end of the interferometer, the interference fringes are a sine comb spectrum on the frequency domain, microwave signals generated by a photoelectric oscillator are modulated onto the interference comb spectrum through an electro-optical modulator to form optical carrier microwave signals, and the optical carrier microwave signals are transmitted to a next device.
As a preferred technical scheme of the invention, the wide-spectrum light source can adopt a Gaussian or rectangular light source as the emission light source, so that the selectivity of the light source emission device is higher.
A method for measuring the thickness of an optical component is characterized in that: the optical path difference of the Mach-Zehnder interferometer is changed before and after the optical component 203 to be tested is inserted into the cavity 103, so that the central frequency of a microwave signal output by the photoelectric oscillator is changed, and the thickness of the optical component to be tested is obtained according to the variation of the central frequency of the microwave signal;
the electric field of the broad spectrum light source 101 can be expressed as:
where ω is the source frequency. The optical power spectral density of the light source can be expressed as:
T(ω)＝|E(ω)|2(2)
after the light source is interfered, after the light path 1 passes through an optical component to be measured, each spectral component generates a certain time delay, which can be expressed as:
E1(ω)＝A1E(ω)ejωΔτ(3)
in the above formula A1For the amplitude attenuation coefficient of the optical path 1, Δ τ is the delay introduced by the optical component to be measured, and can be expressed as:
wherein c is the speed of light, n is the refractive index of the optical fiber, and d is the thickness of the optical component to be measured. The optical path 2 of the interferometer is modulated by a radio frequency signal, and the modulated light can be represented as:
in the above formula A2The amplitude attenuation factor of the optical path 2, ξ the angular frequency of the radio frequency signal,
is the phase difference between the modulated carrier and the sidebands. After the two paths of light pass through a second coupler of the interferometer, the output is as follows:
after the output of the interferometer is delayed by a section of the dispersive optical fiber 106, a delay occurs in the optical carrier, and the electric field transfer function of the delay line can be expressed as:
H(ω)＝|H(ω)|e-jφ(ω)(7)
φ (ω) is the phase introduced by the delay of the dispersive fiber 106, which can be expressed as:
in the formula, τ (ω)0) Has a center frequency of omega0Group delay of time, β is the dispersion of the fiber in ps2The/km, β can be expressed as:
wherein D (ps/km/nm) is the dispersion coefficient of the optical fiber, λ0Is the wavelength of the light source.
The response function of the optoelectronic oscillator output can be expressed as:
HRF(ξ)＝∫T(ω)[H*(ω)H(ω+ξ)+H(ω)H*(ω-ξ)]dω (10)
the response function obtainable from equation (6) — (9) is:
in the above equation, H (ω) is the response function of an ideal optoelectronic oscillator, and can be expressed as:
H(ξ)＝∫T(ω)exp[-jξβL(ω-ω0)]dω (12)
it can be seen that the center frequency of the microwave signal output by the optoelectronic oscillator can be expressed as:
from equation (4), the thickness of the optical device under test is:
from the above formula, the thickness of the optical component to be measured can be obtained according to the frequency of the radio frequency signal output by the optoelectronic oscillator, the central wavelength of the light source, the refractive index of the optical component to be measured, and the dispersion value and length of the dispersion fiber 106.
The invention has the following beneficial effects: the invention relates to a device for measuring the thickness of an optical component, which comprises a Mach-Zehnder interferometer formed by a first optical fiber coupler, an optical component mounting seat to be measured and a second optical fiber coupler, wherein after a wide-spectrum light source passes through the interferometer, when the optical path difference of two arms of the interferometer is within the coherence range of the light source, interference fringes are generated at the output end of the interferometer, and the interference fringes are a sine comb spectrum in the frequency domain; an optoelectronic oscillator loop is formed by an electro-optical modulator, a dispersion optical fiber, a high-speed photoelectric detector, a low-noise amplifier and a microwave power divider, an optical signal is converted into a microwave signal, and the central frequency of the output microwave signal is measured; through the arranged mounting seat of the optical device to be measured, the optical path difference of the Mach-Zehnder interferometer can be changed after the optical device to be measured is inserted, so that the central frequency of a microwave signal output by the photoelectric oscillator is changed, and the thickness of the optical device to be measured is obtained according to the variation of the central frequency of the microwave signal; the invention provides a novel optical component and a method for measuring the thickness of a thin film, the thickness measurement sensitivity of a measurement system can reach the micron level, and the method has good application prospect.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention.
In the drawings:
FIG. 1 is a schematic diagram of the framework of the system of the present invention.
Reference numbers in the figures: 101: a broad spectrum light source; 102: an optical fiber polarizer; 103: a fiber coupler; 104: an optical device mounting base to be tested; 105: an electro-optic modulator; 106: an optical component to be tested; 107: a fiber coupler; 108: a dispersive optical fiber; 109: a high-speed photodetector; 201: low noise is put; 202: a microwave power divider; 203: a frequency spectrograph; 204: and (4) a computer.
Detailed Description
The preferred embodiments of the present invention will be described in conjunction with the accompanying drawings, and it will be understood that they are described herein for the purpose of illustration and explanation and not limitation.
In the description of the present invention, it should be noted that the terms "vertical", "upper", "lower", "horizontal", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.
In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
Example (b): as shown in fig. 1, the present invention provides a device for measuring the thickness of an optical component, in which a broad spectrum light source 101 (which may be a gaussian or rectangular broad spectrum light source) enters an optical fiber coupler 103 through an optical fiber polarizer 102. One output end of the optical fiber coupler is connected with an optical device mounting base 104 to be measured, and an optical device 106 to be measured is inserted into the mounting base for measurement during measurement. The other light from the fiber coupler 103 enters an electro-optical modulator 105, and the output light of the modulator and the output light of the optical device under test mounting base 104 are combined by a fiber coupler 107. The optical fiber coupler 103, the optical device under test mounting base 104, the electro-optical modulator 105 and the optical fiber coupler 107 constitute a mach-zehnder interferometer. Two paths of light of two arms of the interferometer enter a dispersion compensation optical fiber 108 after being combined by an optical fiber coupler, the two paths of light generate time delay after passing through the dispersion compensation optical fiber, a delayed optical signal is subjected to photoelectric conversion by a high-speed photoelectric detector 109 and is amplified by a low-noise amplifier 201, the amplified microwave signal is divided into two paths after passing through a microwave power divider 202, and one path of the amplified microwave signal is injected into an electro-optical modulator 105, so that the electro-optical modulator 105, the optical fiber coupler 107, the dispersion compensation optical fiber 108, the high-speed photoelectric detector 109, the low-noise amplifier 201 and the power divider 202 form a photoelectric oscillator loop, a microwave signal is generated in the loop, and the output frequency of the microwave signal is related to the optical path difference of the two arms of the Mach-Zehnder interferometer. The microwave signal generated by the optoelectronic oscillator is modulated to the optical domain by the electro-optical modulator 105, the optical-carried microwave signal passes through the dispersion compensation fiber 108 and then is incident on the high-speed photoelectric detector 109, the detector converts the optical signal into a microwave signal, the microwave signal is amplified by the low-noise amplifier 201 and then is subjected to power division by the microwave power divider 202, a part of the microwave signal is injected into the electro-optical modulator 105, and a part of the microwave signal is used for measuring the central frequency of the microwave signal output by the optoelectronic oscillator by the frequency spectrograph 203 and recording the change of the central frequency of the microwave signal by the computer 204.
Specifically, the invention relates to a device for measuring the thickness of an optical component, which has the following specific measurement principle: the optical path difference of the Mach-Zehnder interferometer is changed before and after the optical component 203 to be measured is inserted into the optical cavity 103, so that the central frequency of the microwave signal output by the optoelectronic oscillator is changed, and the thickness of the optical component to be measured is obtained according to the variation of the central frequency of the microwave signal.
The electric field of the broad spectrum light source 101 can be expressed as:
where ω is the source frequency. The optical power spectral density of the light source can be expressed as:
T(ω)＝|E(ω)|2(2)
after the light source is interfered, after the light path 1 passes through an optical component to be measured, each spectral component generates a certain time delay, which can be expressed as:
E1(ω)＝A1E(ω)ejωΔτ(3)
in the above formula A1For the amplitude attenuation coefficient of the optical path 1, Δ τ is the delay introduced by the optical component to be measured, and can be expressed as:
wherein c is the speed of light, n is the refractive index of the optical fiber, and d is the thickness of the optical component to be measured. The optical path 2 of the interferometer is modulated by a radio frequency signal, and the modulated light can be represented as:
in the above formula A2The amplitude attenuation factor of the optical path 2, ξ the angular frequency of the radio frequency signal,
is the phase difference between the modulated carrier and the sidebands. After the two paths of light pass through a second coupler of the interferometer, the output is as follows:
after the output of the interferometer is delayed by a section of the dispersive optical fiber 106, a delay occurs in the optical carrier, and the electric field transfer function of the delay line can be expressed as:
H(ω)＝|H(ω)|e-jφ(ω)(7)
φ (ω) is the phase introduced by the delay of the dispersive fiber 106, which can be expressed as:
in the formula, τ (ω)0) Has a center frequency of omega0Group delay of time, β is the dispersion of the fiber in ps2The/km, β can be expressed as:
wherein D (ps/km/nm) is the dispersion coefficient of the optical fiber, λ0Is the wavelength of the light source.
The response function of the optoelectronic oscillator output can be expressed as:
HRF(ξ)＝∫T(ω)[H*(ω)H(ω+ξ)+H(ω)H*(ω-ξ)]dω (10)
the response function obtainable from equation (6) — (9) is:
in the above equation, H (ω) is the response function of an ideal optoelectronic oscillator, and can be expressed as:
H(ξ)＝∫T(ω)exp[-jξβL(ω-ω0)]dω (12)
it can be seen that the center frequency of the microwave signal output by the optoelectronic oscillator can be expressed as:
from equation (4), the thickness of the optical device under test is:
from the above formula, the thickness of the optical component to be measured can be obtained according to the frequency of the radio frequency signal output by the optoelectronic oscillator, the central wavelength of the light source, the refractive index of the optical component to be measured, and the dispersion value and length of the dispersion fiber 106.
The key of the measurement method provided by the invention is to determine various parameters in the equation (14), namely, the length and the dispersion value of a dispersion optical fiber 106 in the photoelectric oscillator are determined firstly, and the optical path difference of two arms of the interferometer is adjusted to ensure that the frequency of a microwave signal output by the photoelectric oscillator is within the measurement frequency range of a common frequency spectrograph (the common frequency spectrograph is not general, and the frequency bandwidth of the common frequency spectrograph is dozens of KHz-26.5 GHz). The resolution of the system can be varied by setting various parameters in the device (14). According to the formula (13), the central frequency 3dB bandwidth of the microwave signal output by the photoelectric oscillator can reach about 80MHz, the frequency resolution of the microwave signal output by the system is 100MHz, the dispersion optical fiber is 1km, the dispersion coefficient is-150 ps/km/nm, the thickness measurement resolution of the test system can reach 20 micrometers when the central wavelength of the light source is 1550nm, and the measurement of the micron-sized thickness can be realized.
The working flow of the thickness measuring system provided by the invention is as follows:
after the power is on, the modulator driving board automatically controls the intensity type optical modulator to work at a linear working point through a program. After the working point of the modulator is determined, the optical device to be tested is not inserted into the optical device mounting seat 103 to be tested, and the central frequency of the microwave signal output by the photoelectric oscillator is recorded as f1. Inserting the optical device to be tested into the optical device mounting seat 103 to be tested, and recording the central frequency f of the microwave signal output by the photoelectric oscillator2. The thickness of the optical component to be measured can be obtained according to the formula (14)
Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that various changes, modifications and substitutions can be made without departing from the spirit and scope of the invention as defined by the appended claims. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (1)
1. A method for measuring the thickness of an optical component is characterized in that: the optical path difference of the Mach-Zehnder interferometer is changed before and after the optical component 203 to be tested is inserted into the optical fiber coupler 103, so that the central frequency of a microwave signal output by the photoelectric oscillator is changed, and the thickness of the optical component to be tested is obtained according to the variation of the central frequency of the microwave signal;
the electric field of the broad spectrum light source 101 can be expressed as:
where ω is the frequency of the light source, the optical power spectral density of the light source can be expressed as:
T(ω)＝|E(ω)|2 (2)
after the light source is interfered, after the light path 1 passes through an optical component to be measured, each spectral component generates a certain time delay, which can be expressed as:
E1(ω)＝A1E(ω)ejωΔτ (3)
in the above formula, a1 is an amplitude attenuation coefficient of the optical path 1, Δ τ is a delay introduced by the optical component to be measured, and can be represented as:
wherein c is the speed of light, n is the refractive index of the optical fiber, d is the thickness of the optical component to be measured, the optical path 2 of the interferometer is modulated by the radio frequency signal, and the modulated light can be expressed as:
in the above formula, a2 is the amplitude attenuation coefficient of the optical path 2, ξ is the angular frequency of the rf signal, and is the phase difference between the modulated carrier and the sideband, and the two paths of light pass through the second coupler of the interferometer and are output as:
after the output of the interferometer is delayed by a section of the dispersive optical fiber 106, a delay occurs in the optical carrier, and the electric field transfer function of the delay line can be expressed as:
H(ω)＝|H(ω)|e-jφ(ω) (7)
φ (ω) is the phase introduced by the delay of the dispersive fiber 106, which can be expressed as:
where τ (ω 0) is the group delay at a center frequency of ω 0, β is the dispersion of the fiber in ps2/km, β can be expressed as:
wherein D (ps/km/nm) is the dispersion coefficient of the optical fiber, λ 0 is the light source wavelength,
the response function of the optoelectronic oscillator output can be expressed as:
HRF(ξ)＝∫T(ω)[H*(ω)H(ω+ξ)+H(ω)H*(ω-ξ)]dω (10)
the response function obtainable from equation (6) — (9) is:
in the above equation, H (ω) is the response function of an ideal optoelectronic oscillator, and can be expressed as:
H(ξ)＝∫T(ω)exp[-jξβL(ω-ω0)]dω (12)
it can be seen that the center frequency of the microwave signal output by the optoelectronic oscillator can be expressed as:
from equation (4), the thickness of the optical device under test is:
from the above formula, the thickness of the optical component to be measured can be obtained according to the frequency of the radio frequency signal output by the optoelectronic oscillator, the central wavelength of the light source, the refractive index of the optical component to be measured, and the dispersion value and length of the dispersion fiber 106;
the optical fiber coupler 103, the optical device mounting base 104 to be tested, the electro-optical modulator 105 and the optical fiber coupler 107 form a Mach-Zehnder interferometer, the electro-optical modulator 105, the optical fiber coupler 107, the dispersion compensation optical fiber 108, the high-speed photoelectric detector 109, the low-noise amplifier 201 and the power divider 202 form a photoelectric oscillator loop;
the microwave signal generated by the optoelectronic oscillator is modulated to the optical domain by the electro-optical modulator 105, the optical-carried microwave signal passes through the dispersion compensation fiber 108 and then is incident on the high-speed photoelectric detector 109, the detector converts the optical signal into a microwave signal, the microwave signal is amplified by the low-noise amplifier 201 and then is subjected to power division by the microwave power divider 202, a part of the microwave signal is injected into the electro-optical modulator 105, and a part of the microwave signal is used for measuring the central frequency of the microwave signal output by the optoelectronic oscillator by the frequency spectrograph 203 and recording the change of the central frequency of the microwave signal by the computer 204.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007298281A (en) * | 2006-04-27 | 2007-11-15 | Nikon Corp | Measuring method and device of surface shape of specimen |
| CN101718519A (en) * | 2008-10-09 | 2010-06-02 | 中国科学院西安光学精密机械研究所 | Index glass ring interferometer |
| CN205482840U (en) * | 2016-01-05 | 2016-08-17 | 哈尔滨理工大学 | Dualbeam component roughness measuring device based on mach -Zehnder |
| CN106646097A (en) * | 2016-11-28 | 2017-05-10 | 华北电力大学 | Transformer winding deformation on-line monitoring system by employing fiber grating strain sensors |
| CN106643522A (en) * | 2016-12-28 | 2017-05-10 | 西南交通大学 | Optical-fiber low-coherence interference displacement demodulation device and method based on photoelectric oscillator |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| US7564562B2 (en) * | 2007-02-23 | 2009-07-21 | Ziebel (US), Inc. | Method for demodulating signals from a dispersive white light interferometric sensor and its application to remote optical sensing |
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007298281A (en) * | 2006-04-27 | 2007-11-15 | Nikon Corp | Measuring method and device of surface shape of specimen |
| CN101718519A (en) * | 2008-10-09 | 2010-06-02 | 中国科学院西安光学精密机械研究所 | Index glass ring interferometer |
| CN205482840U (en) * | 2016-01-05 | 2016-08-17 | 哈尔滨理工大学 | Dualbeam component roughness measuring device based on mach -Zehnder |
| CN106646097A (en) * | 2016-11-28 | 2017-05-10 | 华北电力大学 | Transformer winding deformation on-line monitoring system by employing fiber grating strain sensors |
| CN106643522A (en) * | 2016-12-28 | 2017-05-10 | 西南交通大学 | Optical-fiber low-coherence interference displacement demodulation device and method based on photoelectric oscillator |
Non-Patent Citations (1)
| Title |
|---|
| 宽带可调谐光电振荡器研究;刘辰钧;《中国优秀硕士学位论文全文数据库 信息科技辑》;20150215;第26-29页 * |
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