Process for preparing optical fibre based on single-mode optical fibre to implement different performance of acousto-optic filter

A single-mode optical fiber and filter technology, which is applied in the field of optoelectronics, can solve the problems of limited room for design, limited acousto-optic coupling coefficient, and low degree of overlapping of sound waves and light waves, etc., to reduce power consumption, reduce device volume, Effect of Coupling Conversion Efficiency Improvement

Inactive Publication Date: 2002-05-01
TSINGHUA UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, in a commercially available transmission fiber, the distribution area of ​​the acoustic wave is 125 μm (the outer diameter of the fiber), while the distribution area of ​​the core mode light wave is about 10 μm, and the degree of overlap between the acoustic wave and the light wave is still small, which limits the acousto-optic coupling coefficient. In order to achieve sufficient acousto-optic conversion efficiency, the length of the acousto-optic action zone should not be too short, for example, to obtain image 3 In the results shown, the length of the acousto-optic zone is 30cm
[0013] In short, the advantage of designing and manufacturing acousto-optic filters based on single-mode optical fibers for transmission is that they are compatible with optical fiber communication systems. The disadvantage is that the optical fiber parameters have been fixed, and the corresponding device characteristic parameters have also been determined, leaving little room for design.

Method used

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  • Process for preparing optical fibre based on single-mode optical fibre to implement different performance of acousto-optic filter
  • Process for preparing optical fibre based on single-mode optical fibre to implement different performance of acousto-optic filter
  • Process for preparing optical fibre based on single-mode optical fibre to implement different performance of acousto-optic filter

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0041] The outer diameters of the three sections of cladding matching single-mode optical fiber were partially etched to 72 μm, 56 μm and 25 μm respectively by chemical etching method, and the lengths of the etched sections were all 8 cm. The design method of the outer diameter of the etched optical fiber is: calculate the N value from formula (5) according to the required bandwidth and the allowable active area length, and then use Figure 6 The corresponding curve determines the outer diameter of the etched fiber. The optical fiber used had an original outer diameter of 125 μm, a core diameter of 8.3 μm, and a refractive index difference between the core region and the cladding region of 0.33%. Using hydrofluoric acid with a concentration of about 40%, the etching rate is calibrated at room temperature to be about -60 μm / 30 minutes, and then the etching time is controlled to obtain the required outer diameter of each optical fiber. use Figure 4 The filtered spectra measur...

Embodiment 2

[0045] A section of cladding-matched single-mode fiber identical to that used in Example 1 is partially etched with an outer diameter to 21 μm (by Figure 6 It can be seen that LP 01 -LP 11 cl The critical value of the mode is about 19.5 μm), and the length of the etched segment is 5.5 cm. use Figure 4 The filtered spectrum obtained by the experimental method shown is shown in Figure 8 . The frequency of the sound wave used is 867kHz, the voltage of the piezoelectric ceramic is 2.4V, the power consumption is about 1.1mW, and the measured bandwidth is 349nm.

[0046] It can be seen that when the outer diameter is etched to the vicinity of the critical value, the resulting filtering bandwidth increases by an order of magnitude.

Embodiment 3

[0048] The outer diameter of a section of dispersion compensating optical fiber was locally etched to 50 μm by the same method as in Example 1, and the length of the etched section was 8 cm. The fiber has an original outer diameter of 125 μm and a dispersion of 80 ps / nm / km. use Figure 4 The filter spectrum obtained by the experimental method shown is Figure 11 shown. The sound wave frequency used in the measurement is 1.935MHz, and the piezoelectric ceramic voltage is 20V. In the figure, the central wavelength of peak 111 is 1464.4nm, corresponding to LP 01 -LP 11 cl Mode coupling, the central wavelength of peak 112 is 1590.6nm, corresponding to LP 01 -LP 12 cl mode coupling. The bandwidth of the two peaks is about 2nm, and the distance between the center wavelengths is 126nm. In this way, the tunable range of the single peak region obtained by changing the frequency of the sound wave is 126nm.

[0049] and image 3 Compared with the filter spectrum using the unet...

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Abstract

A process based on single-mode transmitting optical fibre for preparing the optical fibre to implement different performance of acousto-optic filter includes using a commercially available optical fibre for transmission purpose, determining needed external diameter and etching speed, and etching the optical fibre by controlling etch time to change its refractivity in acousto-optical action region. Its advantages are simple process, easy control, high effect, no damage to core of optical fibre, and low loss of optical fibre.

Description

technical field [0001] The invention belongs to the technical field of optoelectronics, in particular to a method for designing and realizing the working performance of an acousto-optic device based on transmission single-mode optical fiber. Background technique [0002] In recent years, with the wide application of wavelength division multiplexing optical communication technology, the corresponding optoelectronic technology industry has become one of the main industries in today's high-tech field. The next step in the development of optical fiber communication systems is broadband, high speed, large capacity and networking. In the future high-speed optical fiber network, in order to overcome the bottleneck effect of the low speed of electronic devices, many control functions originally implemented on the electrical level, such as routing conversion, up and down voice channels, etc., will be implemented on the optical level, which requires A class of dynamically variable wa...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G02B6/124
Inventor 刘小明金厉群赵建辉彭江得
Owner TSINGHUA UNIV
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