CN106372388A - Processing method of output signal of thermoelectric type terahertz detector - Google Patents

Abstract

The invention puts forward a processing method of the output signal of a thermoelectric type terahertz detector, and solves the problems that a time constant obtained by the fitting of the output signal of an existing thermoelectric type terahertz detector in an index form has a large error so as to be unfavorable for the subsequent processing of the output voltage of the thermoelectric type terahertz detector. The processing method puts forward the index form of the ascending curve of the thermoelectric type terahertz detector and a calculation method capable of being quick in response and smooth in processing, and the output voltage signal of the thermoelectric type terahertz detector is processed to improve response speed.

Description

A kind of processing method of electrothermic type terahertz detector output signal

Technical field

The present invention relates to Terahertz technical field of measurement and test, particularly to a kind of electrothermic type terahertz detector output signal Processing method.

Background technology

Electrothermic type detector, with respect to photoelectric detector, has the advantages that spectral response is flat and spectral region width, Have a wide range of applications at aspects such as photoelectricity test, meterings.Due to terahertz wave band wide ranges, design a kind of electrothermic type Terahertz Detector is tested to terahertz signal, is a kind of preferably selection.

In electrothermic type terahertz detector, the rise time is an important parameter, refers to become due to measured step Change, detector output signal rises to the time needed for 90% from the 10% of maximum.The rising of electrothermic type terahertz detector Curve is generally acknowledged to meet theoretical exponential form:

$v_t=v_{max}\[1-\exp (-\frac{t}{\mathrm{\τ}})\]---\left(1\right)$

In formula, v_tIt is the real-time output voltage of the thz laser irradiation detector of certain power；v_maxIt is certain power Thz laser irradiates detector steady-state response voltage；τ is time constant, belongs to the intrinsic ginseng of electrothermic type terahertz detector Number, is typically calculated using exponential fitting；T is the time.

But, the response speed of electrothermic type terahertz detector is slow, and the rise time is about 30s it is impossible to output in real time is tested The actual performance of signal, affects testing efficiency.At present, do not find in prior art to can solve the problem that electrothermic type terahertz detector rings The method answering speed.

In addition, electrothermic type terahertz detector is in actual applications, due to the shadow of the factors such as thermal loss, thermocouple noise Ring, the ascending curve of electrothermic type terahertz detector can not be coincide with theoretical exponential form (1) well.Therefore, using theory There is larger error in the time constant that exponential form (1) matching obtains, be unfavorable for electrothermic type terahertz detector output voltage Subsequent treatment.

Content of the invention

For prior art defect, the present invention proposes a kind of processing method of electrothermic type terahertz detector output signal, Shorten the rise time, improve response speed, the quick change measuring measured signal.

The technical scheme is that and be achieved in that:

A kind of processing method of electrothermic type terahertz detector output signal, comprises the following steps:

Step (1): the ascending curve index of coincidence form of electrothermic type terahertz detector:

$v_t=v_m\left(t\right)+c\·\exp (-\frac{t}{\mathrm{\τ}})\]---\left(2\right)$

In formula: v_tIt is the real-time output voltage of the thz laser irradiation detector of certain power；T is the time；τ is the time Constant, belongs to the intrinsic parameter of electrothermic type terahertz detector；v_mIt is the quick response voltage of electrothermic type terahertz detector；c It is the coefficient of exponential function；

Step (2): the laser using firm power irradiates electrothermic type terahertz detector, is surveyed using oscillograph or voltmeter The output voltage of examination electrothermic type terahertz detector, records ascending curve part；

Step (3): according to the exponential form of formula (2), using method of least square, electrothermic type terahertz detector is exported The ascending curve part of voltage carries out exponential fitting, obtains time constant；

Step (4): according to the real-time output voltage of electrothermic type terahertz detector, calculate electrothermic type terahertz detector Quick response voltage, calculating process is as follows:

$v_m\left(t_k\right)=\left\{\begin{array}{cc}{v}_{t_k}& k=1\\ v_{t_{k-1}}-e^{-\left(t_{k-1}\right)/\mathrm{\τ}}\frac{v_{t_k}-v_{t_{k-1}}}{e^{-t_k/\mathrm{\τ}}-e^{-\left(t_{k-1}\right)/\mathrm{\τ}}}& k=2,3,...,n\end{array}\right.---\left(3\right)$

In formula:When being that the thz laser of certain power irradiates electrothermic type terahertz detector respectively, electrothermic type Terahertz detector is in t_k-1、t_kThe output voltage in moment；T is the time；τ is time constant, belongs to electrothermic type terahertz detector Intrinsic parameter；v_m(t_k) it is electrothermic type terahertz detector in t_kThe quick response voltage in moment；N is that electrothermic type Terahertz is visited Survey the number of device output signal；

Step (5): the quick response voltage of electrothermic type terahertz detector is entered using the method being averaged that gradually adds up Row smoothing processing, the voltage of the electrothermic type terahertz detector after smoothing processing is:

$v\left(t_k\right)=\left\{\begin{array}{cc}\frac{1}{k}\underset{k=1}{\overset{k}{\σ}}{v}_m\left(t_k\right)& k=1,2,\mathrm{...},m-1\\ \frac{1}{m}\underset{k=k-(m-1)}{\overset{k}{\σ}}{v}_m\left(t_k\right)& k=m,m+1,...,n\end{array}\right.---\left(4\right)$

In formula: v (t_k) it is electrothermic type terahertz detector in t_kThe smoothing processing voltage in moment；M is positive integer, and 2≤ m≤n.

Alternatively, described m value is less, and smooth effect is poorer, and the rise time is also less；M value is bigger, and smooth effect is got over Good, the rise time is also bigger.

Alternatively, described m span is 7～10.

Alternatively, as m=8, the rise time of electrothermic type terahertz detector curve of output is 3s.

The invention has the beneficial effects as follows:

Propose the exponential form of electrothermic type terahertz detector ascending curve, and the meter of quick response, smoothing processing Calculation method, by processing to the output voltage signal of electrothermic type terahertz detector, improves response speed.

Brief description

In order to be illustrated more clearly that the embodiment of the present invention or technical scheme of the prior art, below will be to embodiment or existing Have technology description in required use accompanying drawing be briefly described it should be apparent that, drawings in the following description be only this Some embodiments of invention, for those of ordinary skill in the art, on the premise of not paying creative work, acceptable Other accompanying drawings are obtained according to these accompanying drawings.

Fig. 1 is a kind of flow chart of the processing method of present invention electrothermic type terahertz detector output signal；

Fig. 2 is the output voltage curve chart of electrothermic type terahertz detector；

Fig. 3 is the quick response voltage curve of electrothermic type terahertz detector；

Fig. 4 is the smoothing processing voltage curve of electrothermic type terahertz detector；

Fig. 5 is m value and smooth effect, the graph of a relation of rise time.

Specific embodiment

Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete Site preparation description is it is clear that described embodiment is only a part of embodiment of the present invention, rather than whole embodiments.It is based on Embodiment in the present invention, it is every other that those of ordinary skill in the art are obtained under the premise of not making creative work Embodiment, broadly falls into the scope of protection of the invention.

In the prior art, the ascending curve of electrothermic type terahertz detector output voltage is generally acknowledged to meet theory and refers to , there is larger error by the time constant that this functional form matching obtains, be unfavorable for electrothermic type Terahertz in number functional form The subsequent treatment of detector output voltage.In addition, the response speed of electrothermic type terahertz detector is slow, the rise time is generally higher than 30s, it is impossible to export the actual performance of measured signal in real time, affects testing efficiency.

For prior art defect, the present invention proposes a kind of processing method of electrothermic type terahertz detector output signal, Shorten the rise time, improve response speed, the quick change measuring measured signal.

A kind of processing method of electrothermic type terahertz detector output signal of the present invention, as shown in figure 1, include following walking Rapid:

Step (1): the ascending curve of electrothermic type terahertz detector meets following exponential form:

$v_t=v_m\left(t\right)+c\·\exp (-\frac{t}{\mathrm{\τ}})\]---\left(2\right)$

In formula: v_tIt is the real-time output voltage of the thz laser irradiation detector of certain power；T is the time；τ is the time Constant, belongs to the intrinsic parameter of electrothermic type terahertz detector；v_mIt is the quick response voltage of electrothermic type terahertz detector；c It is the coefficient of exponential function.

Step (2): the laser using firm power irradiates electrothermic type terahertz detector, is surveyed using oscillograph or voltmeter The output voltage of examination electrothermic type terahertz detector, records ascending curve part, such as in embodiment illustrated in fig. 2, rise time It is 28.6s.

Step (3): according to the exponential form of formula (2), using method of least square, electrothermic type terahertz detector is exported The ascending curve part of voltage carries out exponential fitting, obtains time constant, in embodiment illustrated in fig. 2, the time constant of curve is 13.4s.

Step (4): according to the real-time output voltage of electrothermic type terahertz detector, calculate electrothermic type terahertz detector Quick response voltage, calculating process is as follows:

$v_m\left(t_k\right)=\left\{\begin{array}{cc}{v}_{t_k}& k=1\\ v_{t_{k-1}}-e^{-\left(t_{k-1}\right)/\mathrm{\τ}}\frac{v_{t_k}-v_{t_{k-1}}}{e^{-t_k/\mathrm{\τ}}-e^{-\left(t_{k-1}\right)/\mathrm{\τ}}}& k=2,3,...,n\end{array}\right.---\left(3\right)$

In formula:When being that the thz laser of certain power irradiates electrothermic type terahertz detector respectively, electrothermic type Terahertz detector is in t_k-1、t_kThe output voltage in moment；T is the time；τ is time constant, belongs to electrothermic type terahertz detector Intrinsic parameter；v_m(t_k) it is electrothermic type terahertz detector in t_kThe quick response voltage in moment；N is that electrothermic type Terahertz is visited Survey the number of device output signal.

The electrothermic type terahertz detector output voltage of embodiment illustrated in fig. 2 is calculated, the quick response electricity of acquisition Pressure is as shown in Figure 3.From figure 3, it can be seen that the quick response voltage pulsation of the electrothermic type terahertz detector of this process acquisition Larger it is impossible to stable assumes measured signal.

Step (5): in order to reduce the fluctuation of quick response voltage, the present invention is using the method being averaged that gradually adds up to heat The quick response voltage of electric type terahertz detector is smoothed, the electrothermic type terahertz detector after smoothing processing Voltage is:

$v\left(t_k\right)=\left\{\begin{array}{cc}\frac{1}{k}\underset{k=1}{\overset{k}{\σ}}{v}_m\left(t_k\right)& k=1,2,\mathrm{...},m-1\\ \frac{1}{m}\underset{k=k-(m-1)}{\overset{k}{\σ}}{v}_m\left(t_k\right)& k=m,m+1,...,n\end{array}\right.---\left(4\right)$

In formula: v (t_k) it is electrothermic type terahertz detector in t_kThe smoothing processing voltage in moment；M is positive integer, and 2≤ m≤n.

Quick response voltage in embodiment illustrated in fig. 3 is smoothed, the smooth voltage of acquisition is as shown in Figure 4. Figure 4, it is seen that after being optimized using smoothing processing method proposed by the present invention, electrothermic type terahertz detector output electricity The undulatory property of pressure has been obtained for improving.

In the present invention, m value is less, and smooth effect is poorer, and the rise time is also less；M value is bigger, and smooth effect is got over Good, the rise time is also bigger, as shown in Figure 5.Therefore, smooth effect and response speed are considered, the m value of the present invention is preferred 7～10.As m=8, the rise time of the electrothermic type terahertz detector curve of output being obtained using the present invention is 3s.

In sum, the present invention, can quickly, accurately by processing to electrothermic type terahertz detector output signal The actual value testing out measured signal.

The present invention proposes the exponential form of electrothermic type terahertz detector ascending curve, and quick response, smooth place The computational methods of reason, by processing to the output voltage signal of electrothermic type terahertz detector, improve response speed.

The foregoing is only presently preferred embodiments of the present invention, not in order to limit the present invention, all essences in the present invention Within god and principle, any modification, equivalent substitution and improvement made etc., should be included within the scope of the present invention.

Claims (4)

1. a kind of processing method of electrothermic type terahertz detector output signal is it is characterised in that comprise the following steps:

Step (1): the ascending curve index of coincidence form of electrothermic type terahertz detector:

$v_t=v_m\left(t\right)+c\·\exp (-\frac{t}{\mathrm{\τ}})\]---\left(2\right)$

In formula: v_tIt is the real-time output voltage of the thz laser irradiation detector of certain power；T is the time；τ is time constant, Belong to the intrinsic parameter of electrothermic type terahertz detector；v_mIt is the quick response voltage of electrothermic type terahertz detector；C is index The coefficient of function；

Step (2): the laser using firm power irradiates electrothermic type terahertz detector, tests heat using oscillograph or voltmeter The output voltage of electric type terahertz detector, records ascending curve part；

Step (3): according to the exponential form of formula (2), using method of least square to electrothermic type terahertz detector output voltage Ascending curve part carry out exponential fitting, obtain time constant；

Step (4): according to the real-time output voltage of electrothermic type terahertz detector, calculate the quick of electrothermic type terahertz detector Response voltage, calculating process is as follows:

$v_m\left(t_k\right)=\left\{\begin{array}{cc}{v}_{t_k}& k=1\\ v_{t_{k-1}}-e^{-\left(t_{k-1}\right)/\mathrm{\τ}}\frac{v_{t_k}-v_{t_{k-1}}}{e^{-t_k/\mathrm{\τ}}-e^{-\left(t_{k-1}\right)/\mathrm{\τ}}}& k=2,3,...,n\end{array}\right.---\left(3\right)$

In formula:When being that the thz laser of certain power irradiates electrothermic type terahertz detector respectively, electrothermic type terahertz Hereby detector is in t_k-1、t_kThe output voltage in moment；T is the time；τ is time constant, belongs to consolidating of electrothermic type terahertz detector There is parameter；v_m(t_k) it is electrothermic type terahertz detector in t_kThe quick response voltage in moment；N is electrothermic type terahertz detector The number of output signal；

Step (5): the quick response voltage of electrothermic type terahertz detector is put down using the method being averaged that gradually adds up Sliding process, the voltage of the electrothermic type terahertz detector after smoothing processing is:

$v\left(t_k\right)=\left\{\begin{array}{cc}\frac{1}{k}\underset{k=1}{\overset{k}{\σ}}{v}_m\left(t_k\right)& k=1,2,...,m-1\\ \frac{1}{m}\underset{k=k-\left(m-1\right)}{\overset{k}{\σ}}{v}_m\left(t_k\right)& k=m,m+1,...,n\end{array}\right.---\left(4\right)$

In formula: v (t_k) it is electrothermic type terahertz detector in t_kThe smoothing processing voltage in moment；M is positive integer, and 2≤m≤ n.

2. as claimed in claim 1 a kind of processing method of electrothermic type terahertz detector output signal it is characterised in that institute State that m value is less, smooth effect is poorer, and the rise time is also less；M value is bigger, and smooth effect is better, and the rise time also gets over Greatly.

3. as claimed in claim 2 a kind of processing method of electrothermic type terahertz detector output signal it is characterised in that institute Stating m span is 7～10.

4. as claimed in claim 3 a kind of processing method of electrothermic type terahertz detector output signal it is characterised in that work as During m=8, the rise time of electrothermic type terahertz detector curve of output is 3s.