CN202522320U

CN202522320U - ORL measurement device

Info

Publication number: CN202522320U
Application number: CN2012201684067U
Authority: CN
Inventors: 夏震宇; 王栋
Original assignee: YUJIN COMMUNICATION (SHANGHAI) CO Ltd
Current assignee: YUJIN COMMUNICATION (SHANGHAI) CO Ltd
Priority date: 2012-04-19
Filing date: 2012-04-19
Publication date: 2012-11-07
Anticipated expiration: 2022-04-19

Abstract

An ORL (optical return loss) measurement device relates to the field of optical measurement devices. The ORL measurement device comprises a laser source (1), an optical splitter (2), an optical power meter (3) for measuring reflected power, a return loss meter (4) and a return loss meter output interface (5), wherein the laser source (1), the optical splitter (2) and the optical power meter (3) for measuring the reflected power are fixedly arranged on the return loss meter (4); the output ends of the laser source (1) and the optical power meter (3) for measuring the reflected power are connected with the two input ends of the optical splitter (2) respectively; and one output end of the optical splitter (2) is connected with the return loss meter output interface (5). The ORL measurement device can measure both the power of incident light with return loss and the insertion loss. The measurement of the insertion loss and return loss is integrated into a piece of equipment, so that the use is convenient.

Description

A kind of smooth return loss measurement mechanism

Technical field:

The utility model relates to measures optical device device field, is specifically related to be used for measuring a kind of smooth return loss measurement mechanism of the distinctive optical properties-return loss of optical device.

Background technology:

When light transmission is in a certain optical device; Always there is part light to be reflected; Echo is mainly produced to factors such as Rayleigh scattering (contaminant particles causes) and directivity by Fresnel reflection (because variations in refractive index causes), back in the optical device, and then the return loss RL of this device is: RL (dB)=-10lg (reflected optical power/incident optical power) ... (1)

And the return loss that OCWR (optical continuous wave reflectometry) method that existing measuring equipment adopts is carried out is measured, and its essential structure is made up of light power meter, light source, optical splitter.

As shown in Figure 1, laser is injected into measured device through optical module, and reflected light guides to light power meter through optical module again, and method of testing was divided into for 4 steps:

A. test lead connection calibrating device is measured reflective power value Pref, if light source output power is PL, the optical module attenuation coefficient is k, and the calibrating device reflectivity is Rref, then:

Prel＝PL·k·Rref+Pp.........(2)

Wherein, Pp is additional reflection power (referring to the reflection of optical module inside and test lead connector etc.).

B. measure additional reflection power P p: test lead is mated, make that the test lead reflective power is 0, can measure additional reflection power P p.

C. test lead connects measured device, measures reflected value Pmeas

Pmeas=(R of PL * k) is tested+Pp ... (3)

R is measured as the measured device reflectivity.

D. calculate return loss RL (dB)

Calculate the return loss value RL of measured device, the dB of unit according to (1), (2), (3).

RL＝-10×log[(Pmeas-Pp)×Rref÷(Pref-Pp)]………(4)

Because it is very high that present this test mode requires calibrating device, calibrating device directly influences the value that records, if long-time the use, calibrating device is certain to produce error, needs often to calibrate and change calibrating device, and this has just increased the use cost of instrument.

The utility model content:

The purpose of the utility model provides a kind of smooth return loss measurement mechanism, and it not only can measure the incident optical power of return loss can also measure Insertion Loss, promptly can be integrated into the Insertion Loss return loss on the equipment, the convenient use.

In order to solve the existing problem of background technology; The utility model is to adopt following technical scheme: it comprises LASER Light Source 1, optical splitter 2, surveys light power meter 3, return loss appearance 4 and the return loss appearance output interface 5 of reflective power; The light power meter 3 of LASER Light Source 1, optical splitter 2 and survey reflective power is fixedly mounted on respectively on the return loss appearance 4; The output terminal of LASER Light Source 1 is connected with two input ends of optical splitter 2 with the output terminal of the light power meter 3 of surveying reflective power respectively, and an output terminal of optical splitter 2 is connected with return loss appearance output interface 5.

Another output terminal of said optical splitter 2 is held for twining, and is the APC end face.

The utility model not only can be measured the incident optical power of return loss can also measure Insertion Loss, promptly can be integrated into the Insertion Loss return loss on the equipment, the convenient use.

Description of drawings:

Fig. 1 is the structural representation in the background technology;

Fig. 2 is the structural representation of the utility model;

Fig. 3 is the structural representation of embodiment two;

Fig. 4 is the circuit theory diagrams of return loss appearance in the utility model;

Fig. 5 is the schematic diagram of the first prime programmable amplifier in the utility model.

Embodiment

Embodiment one:

With reference to Fig. 2; This embodiment adopts following technical scheme: it comprises LASER Light Source 1, optical splitter 2, surveys light power meter 3, return loss appearance 4 and the return loss appearance output interface 5 of reflective power; The light power meter 3 of LASER Light Source 1, optical splitter 2 and survey reflective power is fixedly mounted on respectively on the return loss appearance 4; The output terminal of LASER Light Source 1 is connected with two input ends of optical splitter 2 with the output terminal of the light power meter 3 of surveying reflective power respectively, and an output terminal of optical splitter 2 is connected with return loss appearance output interface 5.

With reference to Fig. 4, comprise the light power meter 3 of surveying reflective power and the power meter 7 of surveying incident light in this embodiment, the light power meter 3 of surveying reflective power is used for measuring reflective power, and the power meter 7 of surveying incident light is used for measuring incident power; The light power meter 3 of said survey reflective power comprises first photo-detector 11, the first prime programmable amplifier 12, first wave filter 13 and first analog to digital converter 14; The output terminal of first photo-detector 11 is connected with the input end of the first prime programmable amplifier 12; The output terminal of the first prime programmable amplifier 12 is connected with the input end of first wave filter 13; The output terminal of first wave filter 13 is connected with the input end of first analog to digital converter 14, and the output terminal of first analog to digital converter 14 is connected with the input end of CPU processor 15; The power meter 7 of said survey incident light comprises second photo-detector 17, the second prime programmable amplifier 18, second wave filter 19 and second analog to digital converter 20; The output terminal of second photo-detector 17 is connected with the input end of the second prime programmable amplifier 18; The output terminal of the second prime programmable amplifier 18 is connected with the input end of second wave filter 19; The output terminal of second wave filter 19 is connected with the input end of second analog to digital converter 20, and the output terminal of second analog to digital converter 20 is connected with the input end of CPU processor 15; Wherein, First photo-detector 11 changes into electric signal to light signal; Be input to first analog to digital converter 14 through first wave filter 13; The value storage that CPU processor 15 collects first analog to digital converter 14 is shown to the user to the return loss value that RAM calculates device again through button and display 16.

With reference to Fig. 5, PIN photodiode 21 changes into electric current to light signal in the described first prime programmable amplifier 12, and operational amplifier 22 amplifies electric current and changes into voltage output, if electric current is I, amplification resistance is R, output voltage U=I*R so;

Thereby CPU processor 15 selects different first to amplify resistance 26, second and amplify resistance the 27, the 3rd and amplify resistance the 28, the 4th and amplify resistance 29 and change gain amplifiers through the adhesive of control first relay 23, second relay 24, the 3rd relay 25.

LASER Light Source 1 sends continuous wave (CW) optical signalling through optical splitter 2 to equipment under test in this embodiment, in return path, measures total CW power of reflection then with the light power meter 3 of surveying reflective power.

This embodiment not only can be measured the incident optical power of return loss can also measure Insertion Loss, promptly can be integrated into the Insertion Loss return loss on the equipment, the convenient use.

Embodiment two:

Referring to Fig. 3; This embodiment is that with the difference of embodiment one it increases power meter 7, calibrating device 8, the measured device 9 that standard testing wire jumper 6 is arranged, survey incident light; The power meter 7 of surveying incident light is connected with return loss appearance output interface 5 through standard testing wire jumper 6; The power meter 7 of incident light is surveyed in calibrating device 8 replacements, and the power meter 7 of incident light is surveyed in measured device 9 replacements.Other composition is identical with embodiment one with annexation.

Wherein, test process comprises three steps: the first step is to carry out the reference of making zero, to confirm to arrive the background power rank of power meter, because this power receives the directivity of three-dB coupler in the influence of following factor: the 1.OCWR; 2.OCWR the reflection coefficient of output port; 3. the backscattering in the main test wire jumper.

When making zero reference, execution need receive on the return loss appearance output interface 5 with a standard testing wire jumper 6; The other end of standard testing wire jumper 6 needs to twine; So just can get rid of the power that the wire jumper end face reflection produces, surveying the performance number that the light power meter 3 of reflective power records this moment is exactly the reflective power summation of system self.

Execute make zero after; Need measure incident power PL, conventional method is to measure reflective power value Pref through connecting calibrating device at test lead, connects calibrating device 8 at return loss appearance output interface 5; Calibrating device 8 is generally selected for use and is ground good FC/UPC wire jumper end face, and uncertainty is generally in 0.2dB.Another kind of desirable calibrating device is that the gold-plated end face of optical fiber (like the HP81000BR of U.S. Hewlett-Packard Corporation) reflectivity can reach 96% (return loss is 0.18dB), and its uncertainty is 0.1dB.If incident power is PL, calibrating device 8 reflectivity are Rref, and the luminous power that power meter 3 records is Pref, then: Pref=PL*Rref;

Can draw incident optical power PL through following formula.This embodiment records incident optical power through another light power meter, and return loss appearance output interface 5 is connected to the power meter 7 of surveying incident light through a standard testing wire jumper 6, so just can record incident power PL.The insertion loss of general standard test wire jumper 6 is less than 0.2dB, so error belongs in the allowed band with interior at 0.2dB.

After recording incident optical power, can test DUT immediately.Measured device 9 is connected to return loss appearance output interface 5 through standard testing wire jumper 6, is noted that in the time of test when using the OCWR measuring method, for guaranteeing to obtain correct result, all need twine rod in two steps, removes the reflections affect of end face.

Claims

1. light return loss measurement mechanism; It is characterized in that it comprises light power meter (3), return loss appearance (4) and the return loss appearance output interface (5) of LASER Light Source (1), optical splitter (2), survey reflective power; The light power meter (3) of LASER Light Source (1), optical splitter (2) and survey reflective power is fixedly mounted on respectively on the return loss appearance (4); The output terminal of LASER Light Source (1) is connected with two input ends of optical splitter (2) with the output terminal of the light power meter (3) of surveying reflective power respectively, and an output terminal of optical splitter (2) is connected with return loss appearance output interface (5).

2. a kind of smooth return loss measurement mechanism according to claim 1 is characterized in that another output terminal of said optical splitter (2) is held for twining, and is the APC end face.

3. a kind of smooth return loss measurement mechanism according to claim 1; It is characterized in that said smooth return loss measurement mechanism comprises the light power meter (3) of surveying reflective power and the power meter (7) of surveying incident light; The light power meter of said survey reflective power (3) comprises first photo-detector (11), the first prime programmable amplifier (12), first wave filter (13) and first analog to digital converter (14); The output terminal of first photo-detector (11) is connected with the input end of the first prime programmable amplifier (12); The output terminal of the first prime programmable amplifier (12) is connected with the input end of first wave filter (13); The output terminal of first wave filter (13) is connected with the input end of first analog to digital converter (14), and the output terminal of first analog to digital converter (14) is connected with the input end of CPU processor (15); The power meter of said survey incident light (7) comprises second photo-detector (17), the second prime programmable amplifier (18), second wave filter (19) and second analog to digital converter (20); The output terminal of second photo-detector (17) is connected with the input end of the second prime programmable amplifier (18); The output terminal of the second prime programmable amplifier (18) is connected with the input end of second wave filter (19); The output terminal of second wave filter (19) is connected with the input end of second analog to digital converter (20), and the output terminal of second analog to digital converter (20) is connected with the input end of CPU processor (15).