JP2007101319A - Measuring instrument of transmission characteristics measuring method of transmission characteristics, program and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain the transmission characteristics of an article to be measured. <P>SOLUTION: The measuring instrument of transmission characteristics includes a continuous wave light source 10 for forming continuous wave light L0, a terahertz light detector 32 for detecting the synthetic light of delay beams, which are delays by a teraheltz light delay circuit 30 from the response light transmitted through or reflected from the measuring target 2 of continuous wave light L0 and the continuous wave light L0, synthesized by a wave synthesizing device 24, and a characteristic measuring part 40 for measuring the transmission characteristics (amplitute characteristics and phase characteristics) of the measuring target 2 on the basis of the detection result of the terahertz photodetector 32. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to measurement of transfer characteristics in a terahertz region of an object to be measured.

  Conventionally, it is known to measure the transfer characteristics of a terahertz region of an object to be measured.

  For example, referring to Fig. 4 (a) of Non-Patent Document 1, a femtosecond laser is used to acquire a transmission or reflection waveform in the time domain of an object to be measured by sampling by the pump-probe method, and fast Fourier transform Devices that obtain transfer characteristics by (FFT) are known.

  Also, referring to FIG. 1 of Patent Document 1, there is also known an apparatus that obtains transfer characteristics of an object to be measured using intensity-modulated terahertz light.

International Publication No. 03/005002 Pamphlet Sakai Kiyomi, “Terahertz Time Domain Spectroscopy”, Spectroscopic Research, 2001, Vol. 50, No. 6, p. 261-273

  However, when a femtosecond laser is used, the reproducibility of femtosecond pulses may not be good. In such a case, in order to obtain a measurement result, a plurality of measurements must be performed and measurement data must be averaged, which takes time. Moreover, since a femtosecond pulse light source is required, the apparatus becomes expensive and large. Furthermore, although the frequency resolution is determined by the reciprocal of the optical delay of the pump light, it is a resolution of several GHz at the maximum.

  In addition, an apparatus using intensity-modulated terahertz light has a complicated configuration, and such an apparatus is large and expensive.

  Therefore, an object of the present invention is to obtain the transfer characteristic of the object to be measured with a simple configuration.

  A transfer characteristic measuring apparatus according to the present invention combines a continuous wave light source that generates continuous wave light, a response light in which the continuous wave light is transmitted or reflected by an object to be measured, and a delayed light obtained by delaying the continuous wave light. The combined light detecting means for detecting the combined light and the characteristic measuring means for measuring the transfer characteristic of the object to be measured based on the detection result of the combined light detecting means.

  According to the transfer characteristic measuring apparatus configured as described above, the continuous wave light source generates continuous wave light. The combined light detection means detects the combined light obtained by combining the response light, which is the continuous wave light transmitted or reflected from the object to be measured, and the delayed light obtained by delaying the continuous wave light. The characteristic measurement unit measures the transfer characteristic of the object to be measured based on the detection result of the combined light detection unit.

  Further, in the transfer characteristic measuring apparatus according to the present invention, the combined light detecting means is a response obtained in a state where the measured object is eliminated from the optical path where the combined light and the continuous wave light travel toward the measured object. Reference response light that is light and reference combined light obtained by combining the delayed light may be detected.

  Further, in the transfer characteristic measuring apparatus according to the present invention, the combined light detection means transmits or reflects the combined light and the reference measured object whose amplitude characteristics and phase characteristics are known. The reference response light and the reference combined light obtained by combining the delayed light may be detected.

  In the transfer characteristic measuring apparatus according to the present invention, the continuous wave light source includes a variable wavelength light source that generates variable wavelength light, a fixed wavelength light source that generates fixed wavelength light, the variable wavelength light, and the fixed wavelength light. And a light generator that generates the continuous wave light having an optical frequency that is a difference between an optical frequency of the variable wavelength light and an optical frequency of the fixed wavelength light.

  In the transfer characteristic measuring apparatus according to the present invention, both the variable wavelength light and the fixed wavelength light may be infrared light.

  In the transfer characteristic measuring apparatus according to the present invention, the continuous wave light source may be a backward wave tube.

In the transfer characteristic measuring apparatus according to the present invention, the characteristic measuring means includes a cosine component deriving means for deriving a cosine component i _cos of the detection result of the combined light detecting means, and an orthogonality of the detection result of the combined light detecting means. An orthogonal component deriving means for deriving a component i _sin , the derived cosine component i _cos and the orthogonal component i _sin, and an amplitude characteristic of the measured object based on (i _cos ² + i _sin ² ) ^1/2 A phase characteristic for deriving a phase characteristic of the object to be measured based on tan ^-1 (i _sin / i _cos ) by receiving the derived cosine component i _cos and the orthogonal component i _sin You may make it have a derivation | leading-out means.

  The present invention detects a continuous wave light source that generates continuous wave light, a response light that is transmitted or reflected from the object to be measured, and a combined light that combines delayed light obtained by delaying the continuous wave light. A method for measuring transfer characteristics by a transfer characteristic measuring device having a combined light detecting means, comprising: a characteristic measuring step for measuring the transfer characteristics of the object to be measured based on a detection result of the combined light detecting means. Composed.

  The present invention detects a continuous wave light source that generates continuous wave light, a response light that is transmitted or reflected from the object to be measured, and a combined light that combines delayed light obtained by delaying the continuous wave light. A program for causing a computer to execute a transfer characteristic measurement process by a transfer characteristic measuring device having a combined light detecting means, wherein the transfer characteristic of the object to be measured is measured based on a detection result of the combined light detecting means A program for causing a computer to execute measurement processing.

  The present invention detects a continuous wave light source that generates continuous wave light, a response light that is transmitted or reflected from the object to be measured, and a combined light that combines delayed light obtained by delaying the continuous wave light. A computer-readable recording medium recording a program for causing a computer to execute a transfer characteristic measurement process by a transfer characteristic measuring device having a combined light detecting means, and based on a detection result of the combined light detecting means, The computer-readable recording medium stores a program for causing a computer to execute a characteristic measurement process for measuring a transfer characteristic of an object to be measured.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a functional block diagram showing a configuration of a transfer characteristic measuring apparatus 1 according to an embodiment of the present invention. When a terahertz light is applied to a device under test (DUT: Device Under Test) 2, the transfer characteristic measuring device 1 measures the light transmitted through the device under test 2 or the light reflected by the device under test 2. This is a device for measuring the transfer characteristics (for example, amplitude characteristics and phase characteristics) of the measurement object 2. The transfer characteristic measuring apparatus 1 includes a continuous wave light source 10, a demultiplexer 22, a multiplexer 24, mirrors 26 and 28, a terahertz light delay circuit 30, a terahertz light detector (combined light detection means) 32, and a characteristic measurement unit 40. Prepare.

  The continuous wave light source 10 generates CW (Continuous Wave) terahertz light. That is, temporally continuous terahertz light is generated. It differs from pulsed light that is discrete in time. The continuous wave light source 10 includes a variable wavelength light source 12, a fixed wavelength light source 14, and a light generator 16.

The variable wavelength light source 12 generates variable wavelength light. The variable wavelength light is infrared light. Further, the variable wavelength light is CW light of the optical frequency f _1.

The fixed wavelength light source 14 generates fixed wavelength light. The fixed wavelength light is infrared light. The fixed wavelength light is CW light of the optical frequency f _2.

The optical frequency f ₁ is changed from f ₂ + Δf _low to _{f 2 + Δf high (Δf low} <Δf high).

The light generator 16 includes an optical multiplexer 16a and a terahertz light generator 16b. The optical multiplexer 16a receives the variable wavelength light and the fixed wavelength light, combines them, and outputs them. The terahertz light generator (light generator) 16b receives an output from the optical multiplexer 16a, and has a difference (f ₁ −f ₂ ) between the optical frequency f ₁ of the variable wavelength light and the optical frequency f ₂ of the fixed wavelength light. A continuous wave light L0 having a frequency is generated. The optical frequency of the continuous wave light L0 changes from Δf _low to Δf _high . The continuous wave light L0 is CW terahertz light, that is, terahertz light continuous in time.

  The terahertz light generator 16b is also called a photomixer. The photomixer can be realized by an optical switch in which a metal parallel transmission line that also serves as an antenna is formed on a low-temperature grown gallium arsenide (LT-GaAs) photoconductive film. The photomixer can be realized by an element in which an antenna is integrated in a single carrier traveling photodiode (UTC-PD).

  The demultiplexer 22 demultiplexes the continuous wave light L0 into a first continuous wave light L1 that travels to the terahertz optical delay circuit 30 and a second continuous wave light L2 that travels to the DUT 2. The second continuous wave light L2 passes through the device under test 2 or is reflected by the device under test 2. The second continuous wave light L2 transmitted through the object to be measured 2 or reflected by the object to be measured 2 is called response light. The response light is given to the multiplexer 24.

  The mirror 26 reflects the first continuous wave light L <b> 1 and applies it to the terahertz optical delay circuit 30. The terahertz light delay circuit 30 delays the first continuous wave light L1. The mirror 28 gives the output of the terahertz optical delay circuit 30 to the multiplexer 24. The light obtained by delaying the first continuous wave light L1 by the terahertz light delay circuit 30 is referred to as delayed light.

  The multiplexer 24 combines the response light and the delayed light. The light obtained by combining the response light and the delayed light is called combined light. Note that the response light obtained in a state in which the device under test 2 is removed from the optical path along which the second continuous wave light L2 travels toward the device under test 2 is referred to as reference response light. That is, the reference response light is obtained by applying the second continuous wave light L2 to the multiplexer 24 as it is (without passing through the DUT 2). The multiplexer 24 combines the reference response light and the delayed light. The light obtained by combining the reference response light and the delayed light is referred to as reference combined light.

  The terahertz light detector (combined light detection means) 32 detects the combined light and the reference combined light. The terahertz light detector 32 can be realized by a bolometer or a Schottky barrier diode (SBD) having sensitivity to terahertz light. The terahertz light detector 32 performs homodyne detection on the combined light and the reference combined light, converts the combined light and the reference combined light into an analog electric signal, and outputs the analog electric signal.

  The characteristic measurement unit 40 measures the transfer characteristic of the DUT 2 based on the detection result of the terahertz light detector 32. The characteristic measurement unit 40 includes an A / D converter 42 and a data processing unit 44. The A / D converter 42 converts the analog electrical signal output from the terahertz photodetector 32 into a digital signal and outputs the digital signal. The data processing unit 44 processes the digital signal output from the A / D converter 42 to obtain the transfer characteristics (amplitude characteristics and phase characteristics in the present embodiment) of the DUT 2.

  FIG. 2 is a functional block diagram showing the configuration of the data processing unit 44. The characteristic measurement unit 40 includes a cosine component deriving unit 442c, an orthogonal component deriving unit 442s, a reference characteristic recording unit 444, an actual measurement characteristic recording unit 446, and a characteristic deriving unit 448.

The cosine component deriving unit 442c derives a cosine component i _cos obtained by converting the detection result of the terahertz light detector 32 into a digital signal.

Quadrature component deriving unit 442s derives the quadrature component i _sin despite converts the detected result of the terahertz light detector 32 into a digital signal. Specifically, the cosine component i _{cos is obtained} by Hilbert transform.

The reference characteristic recording unit 444 records the cosine component i _cos and the orthogonal component i _sin when the terahertz light detector 32 detects the reference response light. That is, the cosine component i _cos and the quadrature component i _sin are recorded when the second continuous wave light L2 is applied to the multiplexer 24 as it is (without passing through the device 2) with the device 2 being removed. .

Actual characteristic recording unit 446, when the terahertz light detector 32 responding light is detected, records the cosine component i _cos and quadrature components i _sin. That is, the cosine component i _cos and the orthogonal component i _sin in a state where the DUT 2 is attached to the transfer characteristic measuring device 1 are recorded.

The characteristic deriving unit 448 receives the cosine component i _cos derived by the cosine component deriving unit 442c and the orthogonal component i _sin derived by the orthogonal component deriving unit 442s from the reference characteristic recording unit 444 and the actually measured characteristic recording unit 446. Based on i _cos ² + i _sin ² ) ^1/2 , the amplitude characteristic of the DUT 2 is derived.

Further, the characteristic deriving unit 448 receives the cosine component i _cos derived by the cosine component deriving unit 442c and the orthogonal component i _sin derived by the orthogonal component deriving unit 442s from the reference characteristic recording unit 444 and the actually measured characteristic recording unit 446. , Tan ⁻¹ (i _sin / i _cos ), the phase characteristic of the DUT 2 is derived.

  Next, the operation of the embodiment of the present invention will be described.

  FIG. 4 is a flowchart showing the operation of the embodiment of the present invention. First, measurement is performed with the DUT 2 attached to the transfer characteristic measuring apparatus 1 (S10).

First, the variable wavelength light source 12 outputs variable wavelength light. The fixed wavelength light source 14 outputs fixed wavelength light. The variable wavelength light and the fixed wavelength light are combined by the optical combiner 16a and supplied to the terahertz light generator 16b. The terahertz light generator 16b generates continuous wave light L0 having an optical frequency of a difference (f ₁ −f ₂ ) between the optical frequency f ₁ of variable wavelength light and the optical frequency f ₂ of the fixed wavelength light. The optical frequency of the continuous wave light changes from Δf _low to Δf _high .

The demultiplexer 22 demultiplexes the continuous wave light L0 into a first continuous wave light L1 that travels to the terahertz optical delay circuit 30 and a second continuous wave light L2 that travels to the DUT 2. _Assuming that the electric field of the first continuous wave light L1 is e _1i (t) and the electric field of the second continuous wave light L2 is e _2i (t), e _1i (t) and e _2i (t) are expressed by the following equation (1). It is expressed in Where t is time, and ω _THz is the angular frequency (in the terahertz region) of the continuous wave light L0.

第二連続波光L2は、被測定物２を透過し、または被測定物２により反射され、応答光となる。応答光は合波器２４に与えられる。また、第一連続波光L1はミラー２６により反射され、テラヘルツ光遅延回路３０に与えられる。テラヘルツ光遅延回路３０により、第一連続波光L1は遅延され、遅延光となる。遅延光は、ミラー２８により反射され、合波器２４に与えられる。

The second continuous wave light L2 passes through the device under test 2 or is reflected by the device under test 2 and becomes response light. The response light is given to the multiplexer 24. Further, the first continuous wave light L 1 is reflected by the mirror 26 and given to the terahertz light delay circuit 30. The first continuous wave light L1 is delayed by the terahertz light delay circuit 30 and becomes delayed light. The delayed light is reflected by the mirror 28 and given to the multiplexer 24.

  Here, if the transfer function of the DUT 2 is Y (ω), Y (ω) is expressed as the following equation (2). The amplitude characteristic of the DUT 2 is A (ω) and the phase characteristic is Φ (ω). Here, ω is the angular frequency of light given to the DUT 2.

また、テラヘルツ光遅延回路３０の遅延時間をT_sとすると、T_sは下記の式（３）のように表される。ただし、Lはテラヘルツ光遅延回路３０の光路長、cは光速、nはテラヘルツ光遅延回路３０の屈折率である。

Further, when the delay time of the terahertz optical delay circuit 30 is T _s , T _s is expressed as the following equation (3). Here, L is the optical path length of the terahertz optical delay circuit 30, c is the speed of light, and n is the refractive index of the terahertz optical delay circuit 30.

そこで、テラヘルツ領域の角周波数ω_THzにおける応答光の電界e_1o(t)および遅延光の電界e_2o(t)は下記の式（４）のように表される。

Therefore, the electric field e _1o (t) of the response light and the electric field e _2o (t) of the delayed light at the angular frequency ω _THz in the terahertz region are expressed by the following equation (4).

合波器２４は、応答光および遅延光を合波し、合波光を出力する。合波光はテラヘルツ光検出器３２により、ある比例定数η₁をもって二乗検波される。テラヘルツ光検出器３２の検波結果i_o(t)は下記の式（５）のように表される。検波結果i_o(t)はアナログ電気信号であり、Ａ／Ｄ変換器４２に与えられる。

The multiplexer 24 combines the response light and the delayed light and outputs the combined light. The combined light is square-detected by the terahertz light detector 32 with a certain proportionality constant η ₁ . Detection result i _o of the terahertz light detector 32 (t) is expressed by the following equation (5). The detection result i _o (t) is an analog electric signal and is supplied to the A / D converter 42.

Ａ／Ｄ変換器４２は、テラヘルツ光検出器３２の出力するアナログ電気信号をデジタル信号に変換して出力する。

The A / D converter 42 converts the analog electrical signal output from the terahertz photodetector 32 into a digital signal and outputs the digital signal.

The cosine component deriving unit 442c derives the cosine component i _cos of the output of the A / D converter 42. The cosine component i _cos is expressed as the following equation (6).

直交成分導出部４４２ｓは、余弦成分i_cosをヒルベルト変換し、Ａ／Ｄ変換器４２の出力の直交成分i_sinを導出する。直交成分i_sinは下記の式（７）のように表される。

The orthogonal component deriving unit 442 s performs Hilbert transform on the cosine component i _cos and derives the orthogonal component i _sin of the output of the A / D converter 42. The orthogonal component _isin is expressed as the following formula (7).

実測特性記録部４４６は、余弦成分i_cosおよび直交成分i_sinを記録する。

The measured characteristic recording unit 446 records the cosine component i _cos and the orthogonal component _isin .

The characteristic deriving unit 448 receives the cosine component i _cos and the orthogonal component i _sin from the measured characteristic recording unit 446. Then, the amplitude characteristic Mag _sam of the DUT 2 is derived as in the following equation (8).

さらに、特性導出部４４８は、下記の式（９）のようにして、被測定物２の振幅特性Θ_samを導出する。

Further, the characteristic deriving unit 448 derives the amplitude characteristic Θ _sam of the DUT 2 as shown in the following equation (9).

次に、伝達特性測定装置１から被測定物２を取り外した状態で測定を行う（Ｓ２０）。測定の際の動作は、被測定物２を取り付けた状態と同様である。ただし、基準特性記録部４４４が、余弦成分i_cosおよび直交成分i_sinを記録する。そして、被測定物２を取り付けないため、被測定物２を取り外した状態の振幅特性Mag_refは、振幅特性Mag_samにおけるA(ω_THz)を１としたものに等しく、下記の式（１０）のように表される。

Next, measurement is performed with the device under test 2 removed from the transfer characteristic measuring apparatus 1 (S20). The operation at the time of measurement is the same as the state in which the DUT 2 is attached. However, the reference characteristic recording unit 444 records the cosine component i _cos and the orthogonal component _isin . Since the device under test 2 is not attached, the amplitude characteristic Mag _ref with the device under test 2 removed is equal to the amplitude characteristic Mag _sam where A (ω _THz ) is 1, and the following equation (10) It is expressed as

また、被測定物２を取り外した状態の位相特性Θ_refは、位相特性Θ_samにおけるΦ(ω_THz)を０としたものに等しく、下記の式（１１）のように表される。

Further, the phase characteristic Θ _ref with the device under test 2 removed is equal to the phase characteristic Θ _sam in which Φ (ω _THz ) is 0, and is expressed by the following equation (11).

最後に、特性導出部４４８が、被測定物２を取り付けた状態の振幅特性Mag_sam、位相特性Θ_samおよび被測定物２を取り外した状態の振幅特性Mag_ref、位相特性Θ_refに基づき、テラヘルツ領域における被測定物２の振幅特性A(ω_THz)、位相特性Φ(ω_THz)を導出する（Ｓ３０）。テラヘルツ領域における被測定物２の振幅特性A(ω_THz)、位相特性Φ(ω_THz)は、下記の式（１２）のようにして導出する。

Finally, the characteristic deriving unit 448 performs terahertz based on the amplitude characteristic Mag _sam with the DUT 2 attached, the phase characteristic Θ _sam, and the amplitude characteristic Mag _ref with the DUT 2 removed, and the phase characteristic Θ _ref. The amplitude characteristic A (ω _THz ) and phase characteristic Φ (ω _THz ) of the DUT 2 in the region are derived (S30). The amplitude characteristic A (ω _THz ) and phase characteristic Φ (ω _THz ) of the DUT 2 in the terahertz region are derived as shown in the following equation (12).

本発明の実施形態によれば、被測定物２の伝達特性を簡単な構成により得ることができる。しかも、連続波光L0の線幅は、可変波長光と固定波長光との光周波数安定度（kHzオーダである）で決まる。よって、kHzオーダの周波数分解能で被測定物２の伝達特性が可能となる。すなわち周波数分解能が高い測定が実施できる。

According to the embodiment of the present invention, the transfer characteristic of the DUT 2 can be obtained with a simple configuration. Moreover, the line width of the continuous wave light L0 is determined by the optical frequency stability (in the order of kHz) between the variable wavelength light and the fixed wavelength light. Therefore, the transfer characteristic of the DUT 2 can be achieved with a frequency resolution of the order of kHz. That is, measurement with high frequency resolution can be performed.

Note that the above-described embodiment can also be realized by using a CW terahertz light source instead of the continuous wave light source 10. FIG. 3 is a functional block diagram showing a configuration of the transfer characteristic measuring apparatus 1 when a CW terahertz light source 19 is used instead of the continuous wave light source 10. The CW terahertz light source 19 can be realized by, for example, a BWO (Backward-Wave Oscillator). The CW terahertz light source 19 generates continuous wave light whose optical frequency changes from Δf _low to Δf _high . The configuration of other parts is the same as that of the above embodiment.

  Further, instead of removing the device under test 2 (S20), a reference device under test having known amplitude characteristics and phase characteristics may be connected instead of the device under test 2.

The characteristic deriving unit 448 derives the amplitude characteristic A (ω _THz ) and the phase characteristic Φ (ω _THz ) of the DUT 2 as follows.

The amplitude characteristic Mag _ref and the phase characteristic Θ _ref in the state in which the reference object is connected are determined by the result of the terahertz light detector 32 detecting the reference response light that is transmitted or reflected by the continuous wave light L0 through the reference object. Can be sought. The amplitude characteristic Mag _ref in the state where the reference object is connected is obtained by replacing A (ω _THz ) in the amplitude characteristic Mag _sam with a known amplitude characteristic, so 2E ₁ E ₂ is replaced with the amplitude characteristic Mag _ref and the known characteristic. It can be obtained from the amplitude characteristic. The phase characteristic Θ _ref in the state in which the reference object is connected is obtained by replacing Φ (ω _THz ) in the phase characteristic Θ _sam with a known phase characteristic, so that −ω _THz T _s is replaced with the phase characteristic Θ _ref and the known It can obtain | require from the phase characteristic.

Therefore, the amplitude characteristic A (ω _THz ) of the DUT 2 from 2E ₁ E ₂ and the amplitude characteristic Mag _sam, and the phase characteristic Φ (ω _THz ) of the DUT 2 from −ω _THz T _s and the phase characteristic Θ _sam Can be derived.

Further, the measurement (S20) with the device under test 2 removed may be performed before the measurement with the device under test 2 attached (S10). If the measurement result with the device under test 2 removed is recorded in the reference characteristic recording unit 444 in advance, immediately after the measurement with the device under test 2 attached (S10), the device under test 2 is measured. It is possible to derive (S30) the amplitude characteristic A (ω _THz ) and the phase characteristic Φ (ω _THz ).

  In the above embodiment, the above-described parts (for example, each part of the data processing unit 44) are added to a computer equipped with a CPU, a hard disk, and a medium (floppy (registered trademark) disk, CD-ROM, etc.) reading device. Read the media that records the program to be implemented and install it on the hard disk. The above embodiment can also be realized by such a method.

It is a functional block diagram which shows the structure of the transfer characteristic measuring apparatus 1 concerning embodiment of this invention. 3 is a functional block diagram showing a configuration of a data processing unit 44. FIG. 2 is a functional block diagram showing a configuration of a transfer characteristic measuring apparatus 1 when a CW terahertz light source 19 is used instead of the continuous wave light source 10. FIG. It is a flowchart which shows operation | movement of embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transfer characteristic measuring device 12 Variable wavelength light source 14 Fixed wavelength light source 16 Light generator 16a Optical multiplexer 16b Terahertz light generator 2 DUT 10 Continuous wave light source 19 CW terahertz light source 22 Demultiplexer 24 Multiplexer 30 Terahertz optical delay Circuit 32 Terahertz photodetector 40 Characteristic measurement unit 44 Data processing unit 442c Cosine component deriving unit 442s Orthogonal component deriving unit 444 Reference characteristic recording unit 446 Actual measurement characteristic recording unit 448 Characteristic deriving unit

Claims (10)

A continuous wave light source that generates continuous wave light;
A combined light detecting means for detecting a combined light obtained by combining the response light that is transmitted or reflected from the object to be measured and the delayed light obtained by delaying the continuous wave light;
Based on the detection result of the combined light detection means, characteristic measurement means for measuring the transfer characteristic of the object to be measured;
A transfer characteristic measuring device. The transfer characteristic measuring device according to claim 1,
The combined light detection means combines the combined light with a reference response light and a delayed light which are response lights obtained in a state where the measured object is removed from an optical path along which the continuous wave light travels toward the measured object. To detect the wave of the combined reference light,
Transfer characteristic measuring device. The transfer characteristic measuring device according to claim 1,
The combined light detection means combines the combined light with a reference response light in which the variable wavelength light is transmitted or reflected from a reference measurement object whose amplitude characteristics and phase characteristics are known, and a reference obtained by combining the delayed light. Detecting the combined light,
Transfer characteristic measuring device. The transfer characteristic measuring device according to any one of claims 1 to 3,
The continuous wave light source is
A variable wavelength light source for generating variable wavelength light;
A fixed wavelength light source for generating fixed wavelength light;
A light generator that receives the variable wavelength light and the fixed wavelength light, and generates the continuous wave light having an optical frequency that is a difference between an optical frequency of the variable wavelength light and an optical frequency of the fixed wavelength light;
A transfer characteristic measuring device. The transfer characteristic measuring device according to claim 4,
The variable wavelength light and the fixed wavelength light are both infrared light.
Transfer characteristic measuring device. The transfer characteristic measuring device according to any one of claims 1 to 3,
The continuous wave light source is a backward wave tube;
Transfer characteristic measuring device. The transfer characteristic measuring device according to any one of claims 1 to 6,
The characteristic measuring means includes
Cosine component deriving means for deriving the cosine component i _cos of the detection result of the combined light detection means;
Orthogonal component derivation means for deriving an orthogonal component i _sin of the detection result of the combined light detection means;
Amplitude characteristic deriving means for receiving the derived cosine component i _cos and the orthogonal component i _sin and deriving the amplitude characteristic of the object to be measured based on (i _cos ² + i _sin ² ) ^1/2 ;
Phase characteristic deriving means for receiving the derived cosine component i _cos and the orthogonal component i _sin and deriving the phase characteristic of the device under test based on tan ⁻¹ (i _sin / i _cos );
A transfer characteristic measuring device. A continuous wave light source for generating continuous wave light; and a combined light detecting means for detecting a response light in which the continuous wave light is transmitted or reflected by an object to be measured and a combined light obtained by combining delayed light obtained by delaying the continuous wave light. A transfer characteristic measuring device having a transfer characteristic measuring device comprising:
A characteristic measurement step of measuring a transfer characteristic of the object to be measured based on a detection result of the combined light detection means;
A transfer characteristic measuring method comprising: A continuous wave light source for generating continuous wave light; and a combined light detecting means for detecting a response light in which the continuous wave light is transmitted or reflected by an object to be measured and a combined light obtained by combining delayed light obtained by delaying the continuous wave light. A program for causing a computer to execute a transfer characteristic measurement process using a transfer characteristic measuring device having:
A characteristic measurement process for measuring a transfer characteristic of the object to be measured based on a detection result of the combined light detection means;
A program that causes a computer to execute. A continuous wave light source for generating continuous wave light; and a combined light detecting means for detecting a response light in which the continuous wave light is transmitted or reflected by an object to be measured and a combined light obtained by combining delayed light obtained by delaying the continuous wave light. A computer-readable recording medium storing a program for causing a computer to execute a transfer characteristic measurement process using a transfer characteristic measuring device having:
A characteristic measurement process for measuring a transfer characteristic of the object to be measured based on a detection result of the combined light detection means;
A computer-readable recording medium on which a program for causing a computer to execute is recorded.

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