A device for testing the faraday center wavelength

Abstract

The utility model discloses a kind of device of testing faraday central wavelength, including ultra-wideband light source, polarization controller, first collimator, polarizer, magnetic bottom plate, analyser, second collimator and spectrometer;The outgoing optical fiber jumper in the ultra-wideband light source, and polarization state is adjusted by being wound to polarization controller, the optical fiber jumper after being adjusted by polarization controller is accessed first collimator, after laser coupling into collimating light, it is used to output 0° polarized state's light beam.The utility model has quick detection function, and central wavelength can be directly read by spectrometer peak by placing the sample to be measured in detection position;With angle compensation function, when faraday central wavelength is not matched, rotate analyser and compensate according to scale indication (such as 1° offset corresponds to polaroid 1° oblique cutting), significantly improve raw material utilization.

Description

Technical Field

[0001] This utility model relates to the field of optical fiber communication technology, and in particular to a device for testing the Faraday center wavelength. Background Technology

[0002] Optical isolators, as key passive components in fiber optic communication and laser systems, primarily function to achieve unidirectional light transmission and protect the light source from back-reflected light interference. Optical isolators based on the Faraday magneto-optical effect rely heavily on the precise matching of the center wavelength (λc) of the Faraday magneto-optical material with the system's operating wavelength. With the development of 5G and data center optical modules towards high speeds of 800G / 1.6T, the requirement for isolation greater than 38dB is becoming increasingly stringent, and traditional testing methods can no longer meet the demands.

[0003] Existing processes require gluing before testing, and the polarizer angle must be repeatedly adjusted to match the Faraday rotation angle. This requires repeated manual adjustments to improve the isolation level. However, this misaligned gluing process can cause the polarizer to misalign again during baking due to the flow of the adhesive (displacement of ±2° after baking). For products with high performance requirements, this method is inefficient and has an unstable yield, resulting in a material waste rate as high as 30%. Utility Model Content

[0004] This invention provides a device for testing the center wavelength of Faraday material, which can quickly detect the center wavelength of Faraday material and complete the screening of Faraday λc (center wavelength) at the material stage.

[0005] To achieve the above objectives, this utility model provides the following technical solution: An apparatus for testing the center wavelength of a Faraday crystal includes an ultra-wideband light source, a polarization controller, a first collimator, a polarizer, a magnetic base plate, an analyzer, a second collimator, and a spectrometer. An optical fiber jumper is led out from the ultra-wideband light source and wound by the polarization controller to adjust the polarization state. The adjusted optical fiber jumper is connected to the first collimator, coupling laser light into collimated light which then passes through the polarizer to output a beam with a 0° polarization state. An analyzer is positioned at a fixed 45° angle to the rear end of the polarizer, and a magnetic base plate is placed between the polarizer and the analyzer to provide a magnetic field in the S→N direction to change the polarization angle of the Faraday sample being tested. The optical signal output from the analyzer is coupled through the second collimator and then transmitted to the spectrometer for calculation and analysis.

[0006] Preferably, the polarizer and the polarizer are mounted on a rotary displacement platform to achieve precise angle adjustment.

[0007] Preferably, both the first and second collimators are fixed by a five-dimensional adjustment frame, which facilitates the adjustment of their positions.

[0008] Preferably, the polarization controller, the first collimator, the polarizer, the magnetic base plate, the analyzer, and the second collimator are all housed in a constant temperature chamber to control the ambient temperature.

[0009] Compared with the prior art, the beneficial effects of this utility model are as follows: This utility model has a rapid detection function, which allows the center wavelength to be directly read from the peak value of the spectrometer by placing the sample to be tested in the detection position; it has an angle compensation function, which allows the analyzer to be rotated and compensated according to the scale indication when the Faraday center wavelength is mismatched (e.g., 1° offset corresponds to 1° oblique cutting of the polarizer), which significantly improves the utilization rate of raw materials; it has a temperature drift calculation function, which reduces external temperature interference and accurately measures the temperature characteristics of materials by introducing a constant temperature chamber to encapsulate key components, thus providing data support for the production of high-performance isolator wafers. Attached Figure Description

[0010] Figure 1 This is a schematic diagram illustrating the principle of an embodiment of the present utility model.

[0011] In the figure: 1. Ultra-wideband light source, 2. Polarization controller, 3. First collimator, 4. Polarizer, 5. Magnetic base plate, 6. Analyzer, 7. Second collimator, 8. Spectrometer, 9. Faraday sample to be tested, 10. Rotational displacement platform, 11. Temperature chamber. Detailed Implementation

[0012] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", "vertical", "horizontal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0013] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0014] like Figure 1As shown, this embodiment of the invention includes an ultra-wideband light source 1, a polarization controller 2, a first collimator 3, a polarizer 4, a magnetic base plate 5, an analyzer 6, a second collimator 7, and a spectrometer 8. An optical fiber jumper is led out from the ultra-wideband light source 1 and wound by the polarization controller 2 to adjust the polarization state. The adjusted optical fiber jumper is connected to the first collimator 3, coupling the laser into collimated light, which then passes through the polarizer 4 to output a beam with a 0° polarization state. An analyzer 6 is located at a fixed angle of 45° to the rear end of the polarizer 4, and a magnetic base plate 5 is positioned between the polarizer 4 and the analyzer 6 to provide a magnetic field in the S→N direction to change the polarization angle of the Faraday sample 9 to be tested. The optical signal output from the analyzer 6 is coupled through the second collimator 7 and then transmitted to the spectrometer 8 for calculation and analysis.

[0015] Preferably, the polarizer 4 and the analyzer 6 are mounted on the rotary displacement platform 10 for precise angle adjustment; the first collimator 3 and the second collimator 7 are both fixed by a five-dimensional adjustment frame for easy position adjustment; the polarization controller 2, the first collimator 3, the polarizer 4, the magnetic base plate 5, the analyzer 6 and the second collimator 7 are all mounted in the constant temperature chamber 11 for controlling the ambient temperature.

[0016] Working principle: First, a fiber optic patch cord exceeding 3 meters in length is led out from the ultra-wideband light source 1 and wound in the polarization controller 2 to adjust the polarization state and reduce the loss of the subsequent polarizer 4. The adjusted patch cord is connected to the first collimator 3, which couples the laser into collimated light, which then passes through the polarizer 4, outputting a beam with a 0-degree polarization state. The analyzer 6 is pre-set to form a fixed 45° angle with the polarizer 4. Specifically, when viewed from the polarizer 4 towards the analyzer 6, the polarization axis of the analyzer 6 is 0 degrees deflected counterclockwise by 45°.

[0017] After confirming the polarization state, the light beam passes through the Faraday sample 9 to be tested. At this time, a magnetic field in the S→N direction is provided by the magnetic base plate 5. According to the law of magneto-optical rotation, the polarized light will rotate 45° clockwise. The rotated polarized light forms a 90° angle with the pre-set analyzer 6, realizing the typical structure of an optical isolator. Finally, the optical signal enters the second collimator 7 for coupling and is transmitted to the spectrometer 8 for calculation and analysis. The center wavelength corresponding to the loss peak is determined by fitting the peak curve.

[0018] After assembly, the first step is to perform alignment. Select a Faraday standard component, such as a 1310FLT Faraday, and conduct standard component testing. The testing procedure is as follows: 1. Sample preparation o Select 5 Faraday samples with acceptable thickness o Prepare 10 pairs of polarizers (0°+45° combination, extinction ratio >45dB).

[0019] 2. Non-destructive testing o Temporary bonding: Use EPO-TEK 353ND epoxy adhesive to bond the Faraday crystal and polarizer (without curing). o Wavelength measurement: Scanning the 1260-1625nm range using a spectrometer (accuracy 0.2nm). o Data recording: Record 50 sets (5×10) λc values ​​and calculate the deviation Δλ from 1310nm.

[0020] 3. Final selection of standard parts The Faraday sample with the smallest average Δλ was selected as the standard.

[0021] Verification test: Repeat 10 times, standard deviation must be <0.5nm.

[0022] The entire process can be carried out in the constant temperature chamber 11 to reduce temperature fluctuations.

[0023] The more samples selected and the more test groups conducted, the more accurate the results. Although 50 sets of tests need to be completed initially, the long-term value of standard parts is significant.

[0024] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A device for testing the Faraday center wavelength, characterized in that: The system includes an ultra-wideband light source, a polarization controller, a first collimator, a polarizer, a magnetic base plate, an analyzer, a second collimator, and a spectrometer. An optical fiber jumper is led out from the ultra-wideband light source and wound by the polarization controller to adjust the polarization state. The adjusted optical fiber jumper is connected to the first collimator, coupling the laser light into collimated light, which then passes through the polarizer to output a beam with a 0° polarization state. An analyzer is located at a fixed 45° angle to the polarizer at its rear end, and a magnetic base plate is positioned between the polarizer and analyzer to provide a magnetic field in the S→N direction to change the polarization angle of the Faraday sample being tested. The optical signal output from the analyzer is coupled through the second collimator and then transmitted to the spectrometer for calculation and analysis.

2. The apparatus for testing the Faraday center wavelength according to claim 1, characterized in that: The polarizer and detector are mounted on a rotary displacement platform to achieve precise angle adjustment.

3. The apparatus for testing the Faraday center wavelength according to claim 1, characterized in that: Both the first and second collimators are fixed by a five-dimensional adjustment frame, which facilitates the adjustment of their positions.

4. The apparatus for testing the Faraday center wavelength according to claim 1, characterized in that: The polarization controller, first collimator, polarizer, magnetic base plate, analyzer, and second collimator are all housed in a constant temperature chamber to control the ambient temperature.

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