CN210089853U

CN210089853U - Optical fiber on-line measurement optical power meter based on bypass waveguide structure

Info

Publication number: CN210089853U
Application number: CN201921145991.7U
Authority: CN
Inventors: 于栋友; 王武楠
Original assignee: Anshan Peak Lan Science And Technology Co Ltd
Current assignee: Anshan Peak Lan Science And Technology Co Ltd
Priority date: 2019-07-16
Filing date: 2019-07-16
Publication date: 2020-02-18
Anticipated expiration: 2029-07-16

Abstract

The utility model relates to an optical fiber on-line measurement optical power meter based on bypass waveguide structure, which is characterized in that the optical power meter comprises an input end optical fiber connector, a section of optical fiber with bypass waveguide processed by femtosecond laser, a patch type photoelectric detector, a data processing and display module and an output end optical fiber connector; after the optical signal passes through the section of optical fiber with the bypass waveguide, the optical signal is divided into two paths, one path of optical signal bypass waveguide output is detected by a patch type photoelectric detector stuck on the optical fiber, the other end of the patch type photoelectric detector is connected with a data processing and display module, and the other path of optical signal is output to an output end optical fiber connector from an optical fiber core. The utility model discloses to the unable on-line measuring's of current optical power meter problem, provided a simple structure, it is with low costs, can realize the real-time on-line measuring's of optical power optic power on-line measuring optical power meter based on bypass waveguide structure under the condition of uninterrupted light path.

Description

Optical fiber on-line measurement optical power meter based on bypass waveguide structure

Technical Field

The utility model belongs to the technical field of photoelectric detection, in particular to optic fibre on-line measuring optical power meter based on bypass waveguide structure.

Background

The optical power meter is used for measuring the optical power, can be used for directly measuring the optical power and can also be used for relatively measuring the optical attenuation, and one optical power meter can evaluate the performance of optical end equipment by measuring the absolute power of a transmitter or an optical network. The use of an optical power meter in combination with a stable light source allows for measurement of connection loss, verification of continuity, and helps to assess the transmission quality of the optical fiber link. The optical power meter is widely applied to communication trunk line laying, equipment maintenance, scientific research and production.

For conventional fiber power monitoring systems, a small portion of the light is directed into another fiber, and then into the photodiode, primarily using a fiber optic splitter. This approach is cumbersome because it typically involves several discrete components. And when using traditional optical power meter to measure certain point optical power on the optic fibre circuit, need cut off this point optical fiber earlier, connect the optical power meter again and measure, weld it again after the measurement is finished, well will guarantee to weld well after the butt fusion simultaneously, the loss that the artificial butt fusion caused does not appear, otherwise still need to weld again. In addition, a large number of movable connectors are plugged in the traditional optical power meter in the testing process, so that the connectors are easily polluted by dust or the connectors are not well butted, and the like, so that the optical channel generates fault points to influence optical signal transmission.

Femtosecond laser direct writing has recently shown great potential for fabricating complex integrated devices and processing planar waveguide structures in fiber cladding. Such a device has the advantage of not requiring bulky optical elements and uninterrupted fiber paths, thus reducing the need for complex alignment, eliminating contamination, and increasing stability.

Aiming at the defects of the traditional optical power meter, the key point is to realize the online measurement of the optical power on the optical fiber line. The utility model provides an optic fibre on-line measuring optical power meter based on bypass waveguide structure, this kind of optic fibre on-line measuring optical power meter can the direct mount on the optical fiber line, can realize the real-time on-line measurement of optical power under the condition of uninterrupted light path, safe and reliable, simple structure has very strong practical value.

SUMMERY OF THE UTILITY MODEL

The utility model provides an optic fibre on-line measuring optical power meter based on bypass waveguide structure, it has the real-time on-line measuring that can realize the optical power under the condition of uninterrupted light path, safe and reliable, advantages such as simple structure.

The utility model discloses a solve the device that technical problem took:

the system is characterized by comprising an input end optical fiber connector, a section of optical fiber which is processed by femtosecond laser and is provided with a bypass waveguide, a patch type photoelectric detector, a data processing and display module and an output end optical fiber connector; one end of the input end optical fiber connector is connected with one end of one section of optical fiber which is processed by femtosecond laser and is provided with a bypass waveguide, an optical signal is divided into two paths after passing through the section of optical fiber which is processed by the femtosecond laser and is provided with the bypass waveguide, one path of optical signal is output from the bypass waveguide etched by the femtosecond laser and is detected by a patch type photoelectric detector stuck on the optical fiber, the other end of the patch type photoelectric detector is connected with the data processing and display module, and the other path of optical signal is output to the output end optical fiber connector from an optical fiber core provided with the bypass waveguide.

The bypass waveguide processed by the femtosecond laser forms an included angle of 5-7 degrees with the fiber core, and the depth and the width are respectively 9-10 microns and 2-3 microns.

The utility model has the advantages that:

the utility model discloses can realize the real-time on-line measuring of luminous power. The apparatus provides a unique method of easily extracting a portion of light from the core of an optical fiber without interrupting the main transmission path. Because the utility model discloses utilize one section through femtosecond laser processing's optic fibre that has bypass waveguide will divide into two the tunnel with input optical signal, wherein the light of the same kind is surveyed the back through SMD photoelectric detector all the way, will change the value that the back electric signal input carries out data processing back output display optical power in data processing and the display module. And the other path of light is still transmitted in the fiber core and is output through the output end optical fiber connector, so that the transmission of optical signals is not interrupted, and the real-time online measurement of the optical power is realized. The utility model discloses simple structure, with low costs, especially easily operation in practical application.

The utility model discloses reduced the needs of complicated alignment, eliminated the pollution to stability has been increased. In optical fibers, there is a continuing need for reliable power splitters to monitor the transmission. Conventionally, such monitoring can be achieved using a fiber optic splitter, with which light is split and collected into a power monitor in one output arm of the splitter, and then a measurement is generated that is proportional to the optical power in the other arm. This method is simple and cost-effective, however, the conventional devices are large in size and limited in application, and the splitter can be directly written inside the optical fiber by the femtosecond laser writing method, so that the optical beam is directly split inside the optical fiber to monitor the optical power propagating in the core of the optical fiber. While eliminating the need for additional devices, reducing the need for complex alignment, eliminating contamination, and increasing stability.

The utility model discloses simple structure, with low costs, especially easily operation in practical application. Because a femtosecond laser direct writing technology is used for directly writing an optical waveguide from the surface of a fiber core to the surface of a cladding in the optical fiber, the refractive index of the optical waveguide is increased after the femtosecond laser writing, and a small part of light in the fiber core can be output from the optical waveguide. Unlike conventional fiber power monitoring systems, a small portion of the light is directed into another fiber, and then into the photodiode, primarily using a fiber optic splitter. This approach is cumbersome because it typically involves several discrete components. Now the utility model discloses the device is direct integrates several discrete subassemblies directly, and the used device number that has significantly reduced, consequently this device simple structure, with low costs, especially easily operate in practical application.

Drawings

Fig. 1 is a schematic structural diagram of an optical fiber on-line measurement optical power meter based on a bypass waveguide structure.

Detailed Description

The present invention will be further described with reference to the accompanying drawings.

As shown in fig. 1, an optical fiber on-line measurement optical power meter based on a bypass waveguide structure comprises an input end optical fiber connector 1, a section of optical fiber 2 with bypass waveguide processed by femtosecond laser, a patch type photoelectric detector 3, a data processing and display module 4 and an output end optical fiber connector 5; one end of an input end optical fiber connector 1 is connected with one end of a section of optical fiber 2 which is processed by femtosecond laser and is provided with a bypass waveguide, an optical signal is divided into two paths after passing through the section of optical fiber 2 which is processed by the femtosecond laser and is provided with the bypass waveguide, one path of optical signal is output from the bypass waveguide etched by the femtosecond laser and is detected by a patch type photoelectric detector 3 stuck on the optical fiber, the other end of the patch type photoelectric detector 3 is connected with a data processing and display module 4, and the other path of optical signal is output to an output end optical fiber 5 connector from an optical fiber core of the optical fiber provided with the bypass waveguide.

The section of the optical fiber processed by the femtosecond laser and provided with the bypass waveguide generates local change of refractive index by utilizing a femtosecond laser direct writing method through nonlinear absorption of ultrafast laser pulses in dielectric materials of a fiber core and a cladding, so that a modification region with the refractive index higher than that of the cladding is defined in the fiber cladding, and an optical waveguide is formed, and the waveguide can interact with light propagating in the fiber core and provides a path for coupling the light in the fiber core from the fiber core to the edge of the optical fiber. In brief, the characteristic that the refractive index of a femtosecond laser focal point irradiation area can be increased is utilized, femtosecond laser is used for writing an optical waveguide from the surface of a fiber core to the surface of a cladding on a section of optical fiber, the refractive index of the optical waveguide is increased after the femtosecond laser is written, and a small part of light in the fiber core can be output from the optical waveguide.

The utility model discloses the working method of system does: an optical signal is input from an input end optical fiber connector to a section of femtosecond laser processed optical fiber with a bypass waveguide, the section of femtosecond laser processed optical fiber with the bypass waveguide generates local change of refractive index through nonlinear absorption of ultrafast laser pulse in the dielectric materials of a fiber core and a cladding by using a femtosecond laser direct writing method, so that a modification region with the refractive index higher than that of the cladding is defined in the fiber cladding, and a waveguide is formed, and the waveguide can interact with light propagating in the fiber core and provides a path for coupling the light from the fiber core to the edge of the optical fiber. In brief, the characteristic that the refractive index of a femtosecond laser focal point irradiation area can be increased is utilized, femtosecond laser is used for writing an optical waveguide from the surface of a fiber core to the surface of a cladding on a section of optical fiber, the refractive index of the optical waveguide is increased after the femtosecond laser is written, and a small part of light in the fiber core can be output from the optical waveguide. After the light output from the optical waveguide is detected by the patch type photoelectric detector, the converted electric signal is input into the data processing and displaying module for data processing, and then the value of the display optical power is output. And the other most of light is still transmitted in the fiber core and is output through the output end optical fiber connector, so that the optical signal transmission is not interrupted.

The key technology of the device for realizing the optical power online measurement of the optical fiber comprises the following steps:

a femtosecond laser is used to write an optical waveguide from the core surface to the cladding surface on a length of optical fiber. This is achieved by using femtosecond laser direct writing method to generate local variation of refractive index by nonlinear absorption of ultrafast laser pulses inside the fiber core and the dielectric material of the cladding, so that a modified region with refractive index higher than that of the cladding is defined inside the fiber cladding, and a waveguide is formed, which can interact with light propagating in the core, providing a path for coupling light from the core to the edge of the fiber. After the femtosecond laser writing, the refractive index of the optical waveguide will be increased, but the loss will be caused to the optical signal transmission. The loss of the optical waveguide for the femtosecond laser writing is related to the pulse energy and the scanning speed of the femtosecond laser, so that the loss is reduced by selecting the proper pulse energy and scanning speed of the femtosecond laser.

The bypass waveguide is at an angle to the core. The included angle between the processed bypass waveguide and the fiber core cannot be too large or too small, the too small angle can cause the device size to be too large, and the too large angle can cause the transmission loss to be greatly increased. The light splitting can be well realized by selecting the included angle of about 5-7 degrees, and the device can not be overlong and the transmission loss can not be overlarge.

The thickness range of the bypass waveguide. Different thicknesses of the bypass waveguide have different splitting ratios, too thick results in too high splitting ratio to influence the transmission of optical signals on a line, and too thin results in too low splitting ratio to cause too low power of optical signals transmitted by the bypass waveguide to be detected by the patch type photoelectric detector. Suitable splitting ratios can be obtained by selecting the depth and width to be 9-10 microns and 2-3 microns, respectively.

In one embodiment of the present invention, the femtosecond laser system provides a collimated beam focused at 1035nm wavelength, and the power of the laser pulse generated is 70mW, and the repetition frequency and the pulse duration are 510KHz and 260fs, respectively. The angle between the processed bypass waveguide and the fiber core is 6 degrees, the depth and the width are respectively 9.4 mu m and 2.5 mu m, and the ratio of the splitting power to the input optical power is 3.0 percent.

The basic principles and essential features of the invention have been shown and described above, and various changes and modifications may be made without departing from the spirit and scope of the invention, all of which fall within the scope of the claimed invention.

Claims

1. An optical fiber on-line measurement optical power meter based on a bypass waveguide structure is characterized by comprising an input end optical fiber connector, a section of optical fiber which is processed by femtosecond laser and is provided with a bypass waveguide, a patch type photoelectric detector, a data processing and display module and an output end optical fiber connector; one end of the input end optical fiber connector is connected with one end of a section of optical fiber which is processed by femtosecond laser and is provided with a bypass waveguide, an optical signal is divided into two paths after passing through the section of optical fiber which is processed by the femtosecond laser and is provided with the bypass waveguide, one path of optical signal is output from the bypass waveguide etched by the femtosecond laser and is detected by a patch type photoelectric detector which is stuck on the optical fiber, the other end of the patch type photoelectric detector is connected with the data processing and display module, and the other path of optical signal is output to the output end optical fiber connector from the optical fiber core provided with the; the bypass waveguide processed by the femtosecond laser forms an included angle of 5-7 degrees with the fiber core, and the depth and the width are respectively 9-10 microns and 2-3 microns.