CN100516772C - Optical signal processing device and method - Google Patents

Abstract

Translated fromChinese

一种光学信号处理装置，包括一迈克尔逊干涉仪及一信号处理电路，该迈克尔逊干涉仪包括一光源、一光出射/光反射系统、一基准面及一相位调节器；该信号处理电路包括一正弦波产生器、一光感测器、一前置放大电路、一ω频率滤波电路、一2ω频率滤波电路及一光敏电阻放大器。本发明采用与入射光强度无关的光相位差信号检取方法，进行光学信号处理时可避免入射光强度因环境变化的不稳定因素而造成的信号检取误差。

An optical signal processing device includes a Michelson interferometer and a signal processing circuit, the Michelson interferometer includes a light source, a light emission/light reflection system, a reference plane and a phase regulator; the signal processing circuit includes A sine wave generator, a light sensor, a preamplifier circuit, an ω frequency filter circuit, a 2ω frequency filter circuit and a photoresistor amplifier. The invention adopts an optical phase difference signal retrieval method that has nothing to do with incident light intensity, and can avoid signal retrieval errors caused by unstable factors of environmental changes in incident light intensity during optical signal processing.

Description

Processing device of optical signal and method

[technical field]

The present invention is about a kind of processing device of optical signal and method, especially about a kind of optical phase difference signal processing apparatus and method that has nothing to do with incident intensity.

[background technology]

Generally with light signal during as the medium of signal Processing, physical parameter of desiring to search such as temperature, distance, rotating speed etc. often are present in intensity, frequency or the phase place of light signal, and be not to separately exist in light intensity, light frequency or the light phase in each, therefore, from light signal, search out and be proportional to the signal difficulty relatively often of waiting to search physical parameter.In addition, even physical parameter to be detected only is hidden in light intensity, light frequency or the light phase in each, because the variation disturbance of environment causes the variation of other two signals also can influence interference signal to be detected, thus the error that can cause signal to search.If each irrelevant optical signal processing method in a kind of and light intensity, light frequency or the light phase can be provided, will reduce the error that light signal is searched.

In view of this, provide a kind of processing device of optical signal and method that has nothing to do with incident intensity to be necessity in fact.

[summary of the invention]

The object of the present invention is to provide a kind of processing device of optical signal that has nothing to do with incident intensity.

Another object of the present invention is to provide a kind of optical signal processing method that has nothing to do with incident intensity.

For realizing purpose of the present invention, a kind of processing device of optical signal is provided, comprise a Michelson interferometer and a signal processing circuit, this Michelson interferometer comprises a reference field, it is provided with determinand; One light source, it can launch a light beam as determinand; One smooth outgoing/reflective optical assembly, it is between this light source and determinand, and its outgoing beam with light source is divided into the suitable two-beam of intensity; And a phase regulator, the phase place of its scalable Michelson interferometer; This signal processing circuit comprises a sine-wave producer, an OPTICAL SENSORS, a pre-amplification circuit, a ω frequency filter circuit, one 2 ω frequency filter circuits and a photoresistance amplifier, wherein, sine-wave producer is connected with the phase regulator of Michelson interferometer, the signal of OPTICAL SENSORS sensor light outgoing/reflective optical assembly outgoing beam also is converted into electric signal output, this electric signal is through behind the pre-amplification circuit, pass through ω frequency filter circuit, 2 ω frequency filter circuits more respectively, after the photoresistance amplifier is handled back output.

For realizing purpose of the present invention, a kind of optical signal processing method is provided, and is to use for described processing device of optical signal, may further comprise the steps: a Michelson interferometer is provided, one determinand is set on its reference field, thereby makes Michelson interferometer form an interfering beam; Use sine-wave producer that the phase regulator of Michelson interferometer is modulated, it is poor to make Michelson interferometer produce a light phase; Using OPTICAL SENSORS to detect described interfering beam signal is converted into electric signal and handles via pre-amplification circuit; Use filtering circuit that described electric signal is handled to obtain voltage signal; Use the photoresistance amplifier that described voltage signal is handled the final linear signal that obtains determinand thickness.

Compare prior art, a kind of processing device of optical signal and method that has nothing to do with incident intensity of the present invention, adopt with the irrelevant light phase difference signal of incident intensity and search method, carry out to avoid when optical signalling is handled incident intensity to search error because of the signal that the labile factor of environmental change causes.

[description of drawings]

Fig. 1 is the synoptic diagram of a kind of processing device of optical signal of the present invention.

[embodiment]

Please refer to shown in Figure 1ly, processing device of optical signal of the present invention comprises a Michelson interferometer (not label) and a signal processing circuit (not label).

This Michelson interferometer comprises reference field 10, light source 11, light outgoing/reflective optical assembly 12, collimating apparatus 13a, 13b, phase regulator 14 and pedestal 15, wherein, this light source 11 is launched a light beam to determinand, this light outgoing/reflective optical assembly 12 is arranged in the light path of this light source 11, its outgoing beam with light source 11 is divided into the suitable two-beam of intensity and directive undetected object and reference field 10, this collimating apparatus 13a, 13b is arranged on the pedestal 15, and it is between light outgoing/reflective optical assembly 12 and determinand, and pedestal 15 is used to finely tune collimating apparatus 13a, the position of 13b is located in the light path between light outgoing/reflective optical assembly 12 and determinand.

This signal processing circuit comprises sine-wave producer 20, OPTICAL SENSORS 21, pre-amplification circuit 22, ω frequency filter circuit 23,2 ω frequency filter circuits 24 and photoresistance amplifier 25, wherein, sine-wave producer 20 is connected with phase regulator 14, but the signal of OPTICAL SENSORS 21 sensor light outgoing/reflective optical assemblies 12 outgoing beams also is converted into electric signal output, this electric signal is through behind the pre-amplification circuit 22, pass through ω frequency filter circuit 23,2 ω frequency filter circuits 24 more respectively, after photoresistance amplifier 25 is handled back output.This ω frequency filter circuit 23 and 2 ω frequency filter circuits 24 are connected in parallel between pre-amplification circuit 22 and the photoresistance amplifier 25.

In the present embodiment, a film 30 is arranged on the reference field 10, the thickness of this film 30 is d.Light source 11 emitted light beams are divided into the suitable light beam a of intensity, light beam b after by light outgoing/reflective optical assembly 12.Light beam a is through being mapped on the film 30 and reflecting to form light beam a ' behind the collimating apparatus 13a, light beam a ' passes through directive light outgoing/reflective optical assembly 12 behind the collimating apparatus 13a once more.Light beam b is mapped on the reference field behind collimating apparatus 13b and reflects to form light beam b ', light beam b ' passes through directive light outgoing/reflective optical assembly 12 behind the collimating apparatus 13b once more, and forming synthetic interfering beam with light beam a ', the interference light signal of this interfering beam is A (1+Bcos (Φ θ+knd)).Wherein, A, B are the constant relevant with intensity of reflected light; Φ θ is that the proper phase of Michelson interferometer is poor, is made as 0 at this; K is a wave number; N is a natural number.The sine-wave producer 20 of signal processing circuit, its phase regulator 14 to Michelson interferometer is modulated, and makes Michelson interferometer produce a light phase difference sin ω t.Therefore, optical interference signals becomes A (1+Bcos (sin ω t+knd)).

Transfer electric signal to behind OPTICAL SENSORS 21 and the pre-amplification circuit 22 in optical interference signals A (1+Bcos (sin ω t+knd)) the process signal processing circuit, this electric signal comprises DC terms, ω frequency item, 2 ω frequency items and many ω high-frequency harmonic item compositions.Usually the value of nd is very little, and after decomposing through Fourier (Fourier) function, can get ω frequency item composition is Csinnd, and 2 ω frequency item compositions are Ccosnd, wherein, C be one with the irrelevant constant of intensity of reflected light.After this electric signal passes through ω frequency filter circuit 23 and 2 ω frequency filter circuits 24 respectively, obtain the voltage signal of direct ratio and sinnd and cosnd respectively.This voltage signal after photoresistance amplifier 25 is handled, can obtain one with intensity of reflected light irrelevant and with the linear voltage signal of tannd.Usually, nd is very little, and tannd ≈ nd then obtain the linear signal of the thickness d of film 30 thus, and this linear signal is irrelevant with the intensity of going into light source 11.

Claims (7)

1. processing device of optical signal, it is characterized in that: described processing device of optical signal comprises a Michelson interferometer and a signal processing circuit, wherein, described Michelson interferometer comprises a light source, a smooth outgoing/reflective optical assembly, a reference field and a phase regulator, reference field is provided with determinand, light source can be launched a light beam, light outgoing/reflective optical assembly is between this light source and reference field, the outgoing beam of light source is divided into the suitable two-beam of intensity, and phase regulator can be regulated the phase place of Michelson interferometer; Described signal processing circuit comprises a sine-wave producer, one OPTICAL SENSORS, one pre-amplification circuit, one ω frequency filter circuit, one 2 ω frequency filter circuits and a photoresistance amplifier, sine-wave producer is connected with the phase regulator of Michelson interferometer, it is modulated phase regulator, it is poor to make Michelson interferometer produce a light phase, the outgoing beam signal of OPTICAL SENSORS sensor light outgoing/reflective optical assembly also is converted into electric signal output, this electric signal passes through the ω frequency filter circuit respectively again through behind the pre-amplification circuit, exporting the photoresistance amplifier to after 2 ω frequency filter circuits are handled handles.

2. processing device of optical signal as claimed in claim 1 is characterized in that: described Michelson interferometer further comprises a pedestal, and it is provided with a plurality of collimating apparatuss, and this collimating apparatus is arranged in the light path between light outgoing/reflective optical assembly and determinand.

3. processing device of optical signal as claimed in claim 1, it is characterized in that: be connected output one of photoresistance amplifier and the linear voltage signal of determinand thickness after described ω frequency filter circuit and the 2 ω frequency filter circuit parallel connections with the photoresistance amplifier.

4. optical signal processing method may further comprise the steps:

One Michelson interferometer is provided, a determinand is set on its reference field, thereby make Michelson interferometer form an interfering beam;

Use sine-wave producer that the phase regulator of Michelson interferometer is modulated, it is poor to make Michelson interferometer produce a light phase;

Use OPTICAL SENSORS to detect described interfering beam signal, and be converted into electric signal and send by pre-amplification circuit and handle;

Use ω frequency filter circuit and 2 ω frequency filter circuits respectively the electric signal of pre-amplification circuit output to be handled;

Use the photoresistance amplifier that the electric signal of ω frequency filter circuit and the output of 2 ω frequency filter circuits is handled to obtain and the linear voltage signal of determinand thickness.

5. optical signal processing method as claimed in claim 4, it is characterized in that: described Michelson interferometer further comprises a light source and a smooth outgoing/reflective optical assembly, this light source can be launched a light beam, this light outgoing/reflective optical assembly is divided into the suitable two-beam of intensity with the outgoing beam of light source between this light source and determinand.

6. optical signal processing method as claimed in claim 5 is characterized in that: described Michelson interferometer further comprises a pedestal, and it is provided with a plurality of collimating apparatuss, and this collimating apparatus is arranged in the light path between light outgoing/reflective optical assembly and determinand.

7. optical signal processing method as claimed in claim 4 is characterized in that: described ω frequency filter circuit and 2 ω frequency filter circuits are connected in parallel between pre-amplification circuit and the photoresistance amplifier.