TWI487961B - Microfiber coupler - Google Patents

Description

Micro-fiber coupling structure

This invention relates to a microfiber coupling structure, and more particularly to a microfiber coupling structure having a microfiber coil.

Since the introduction of the micro-fiber coil resonator in the US Fiber Optic Laboratory (OFS Laboratories) in 2005, it has attracted the attention of researchers in related fields. Since the micro-fiber is used instead of the general fiber to form the coil, the flexible radius of the micro-fiber coil can be much reduced. In addition, since the micro-fiber coil can be reciprocally wound in a three-dimensional structure, the micro-fiber coil can achieve a certain coupling length in a small range, and thus the volume of the micro-fiber coil resonator can be reduced, thereby achieving a small product. Purpose.

In general, microfiber coil resonators can be used in laser systems as well as in sensing. For example, an optical resonant cavity can be used to limit photons in a laser system, and its ability to limit photons can be judged by a quality factor (Q). The quality factor is defined as the ratio of the energy stored in the optical cavity to the energy lost in a single cycle. Resonators with high quality factors provide an advantageous condition for lasers, and the higher the quality factor, the easier it is to excite the laser. on the other hand, Microfiber resonators with high quality factors can also be used in the sensing field to allow the sensor to detect even smaller changes. In addition, the micro-fiber resonator with high quality factor can also make the light stay in the cavity of the micro-fiber coil longer, and also enhance the nonlinear effect of the cavity, which can be applied to the field of fiber sensing and nonlinear optics. .

Therefore, how to improve the quality factor of the micro-fiber resonator as much as possible has become one of the goals of many researchers in the field of optoelectronics.

The present invention provides a microfiber coupling structure that has high quality factors.

A microfiber coupling structure of the present invention includes a rod body and a micro fiber. The microfiber is wound on the rod to form a first microfiber structure layer and a second microfiber structure layer. The first microfiber structure layer surrounds the rod and includes a plurality of first microfiber coils. The second microfiber structure layer surrounds the first microfiber structure layer and includes at least one second microfiber coil. The first microfiber coils and the at least one second microfiber coil are coupled to each other to form a microfiber coil resonant cavity.

In an embodiment of the invention, the number of the first micro-fiber coils is two, and the number of the at least one second micro-fiber coils is one.

In an embodiment of the invention, the number of the first micro-fiber coils is three, and the number of the at least one second micro-fiber coils is two.

In an embodiment of the invention, the first micro-fiber coil and the at least one second micro-fiber coil are in contact with each other.

In an embodiment of the invention, the rod body has an extending direction, The microfiber is wound on the rod in a winding direction, and the angle between the winding direction and the extending direction falls between 85 degrees and 95 degrees.

In an embodiment of the invention, the diameter of the microfibers described above falls within the range of 1 micrometer to 5 micrometers.

Based on the above, the micro-fiber coil resonator formed by the micro-fiber coupling structure of the present invention can be coupled to each other by the first micro-fiber coil of the first micro-fiber structure layer and the second micro-fiber coil of the second micro-fiber structure layer. To increase the probability of leaving light in the cavity of the micro-fiber coil, and thereby improve the quality factor of the cavity of the micro-fiber coil.

The above described features and advantages of the invention will be apparent from the following description.

100, 300‧‧‧Microfiber coupling structure

110‧‧‧ rod body

120‧‧‧First micro-fiber structure layer

121‧‧‧First micro fiber coil

130‧‧‧Second micro-fiber structure layer

131‧‧‧Second micro fiber coil

200‧‧‧Making device for micro-fiber coupling structure

210‧‧‧Fiber Bracket

220‧‧‧Rotating unit

230‧‧‧High precision stepper motor

240‧‧‧Image detection device

241‧‧‧ Objective lens

242‧‧‧Sensor components

E1‧‧‧ extending direction

DW‧‧‧ winding direction

MF‧‧‧Microfiber

Θ‧‧‧ angle

1A is a schematic diagram of a micro-fiber coupling structure according to an embodiment of the present invention.

FIG. 1B is a schematic structural diagram of a device for fabricating a micro-fiber coupling structure according to an embodiment of the invention.

1C is a spectrogram of the microfiber coupling structure of FIG. 1A.

2 is a schematic diagram of a micro-fiber coupling structure according to another embodiment of the present invention.

1A is a schematic diagram of a micro-fiber coupling structure according to an embodiment of the present invention. 1B is a diagram of a manufacturing apparatus of a micro-fiber coupling structure according to an embodiment of the present invention; Schematic diagram of the architecture. Referring to FIG. 1A and FIG. 1B , the micro-fiber coupling structure 100 of the embodiment includes a rod 110 and a micro-fiber MF. In the present embodiment, the material of the rod body is, for example, silica, and the surface thereof is coated with polydimethylsiloxane (PDMS). Further, in the present embodiment, the diameter of the microfiber MF falls within the range of 1 micrometer to 5 micrometers, and the diameter of the stem 110 falls within the range of 1.6 mm to 2.0 mm. In more detail, the microfiber MF of the present embodiment has a diameter of 3 μm, and the rod body 110 has a diameter of 1.8 mm. It should be noted that the above various parameters are merely illustrative, and are not intended to limit the invention.

Specifically, in the present embodiment, the micro-fiber coupling structure 100 can be fabricated by a fabrication apparatus 200 of a micro-fiber coupling structure. In detail, the micro-fiber coupling structure manufacturing apparatus 200 includes a fiber holder 210, a rotating unit 220, a high-precision stepping motor 230, and an image detecting device 240. For example, in the embodiment, the image detecting device 240 can include an objective lens 241 having a long working distance and a sensing component 242, but the invention is not limited thereto.

In the present embodiment, the rod 110 can be fixed to the center of the rotating unit 220, for example, and one end of the microfiber MF is coupled to the fiber holder 210, and the other end of the micro fiber MF is coupled to the high precision stepping motor 230. Thus, when the rotating unit 220 rotates, a plurality of micro-fiber coil resonant cavities can be formed on the rod body 110 by controlling the concentricity of the rotating shaft of the rotating unit 220 and the movement of the high-precision stepping motor 230. Moreover, since the manufacturing device 200 of the micro-fiber coupling structure has good concentricity and stability, and the use of the image detecting device 240, the micro fiber MF can be The process of winding on the rod 110 allows for immediate observation, which helps to detect errors early, so that the gap between the resonators of the respective micro-fiber coils can be accurately controlled. In more detail, in the embodiment, the rod body 110 has an extending direction E1, and the microfiber MF is wound on the rod body 110 in a winding direction DW, and the angle θ between the winding direction DW and the extending direction E1 falls at 85. Between degrees and 95 degrees. It should be noted that the above various parameters are merely illustrative, and are not intended to limit the invention. As such, the micro-fiber coupling structure 100 as shown in FIG. 1A will be formed on the shaft 110.

In more detail, as shown in FIG. 1A, in the embodiment, the microfiber MF is wound on the rod 110 to form a first micro-fiber structure layer 120 and a second micro-fiber structure layer 130. The first micro-fiber structure layer 120 surrounds the rod 110 and includes a plurality of first micro-fiber coils 121. The second micro-fiber structure layer 130 surrounds the first micro-fiber structure layer 120 and includes at least one second micro-fiber coil 131. In the present embodiment, the number of the first micro-fiber coils 121 is larger than the number of the second micro-fiber coils 131. For example, in the embodiment, the number of the first micro-fiber coils 121 is two, and the number of the second micro-fiber coils 131 is one, but the embodiment is not limited thereto.

Further, the first micro-fiber coils 121 and the at least one second micro-fiber coils 131 are coupled to each other to form a micro-fiber coil resonant cavity. In more detail, as shown in FIG. 1A, the first micro-fiber coil 121 and the second micro-fiber coil 131 are in contact with each other. In other words, in this embodiment, the contact area between the micro-fiber coils (ie, the first micro-fiber coil 121 and the second micro-fiber coil 131) can be increased by the structural design of the plurality of micro-fiber structure layers, thereby increasing The probability of light remaining in the cavity of the micro-fiber coil and thereby improving the quality factor of the cavity of the micro-fiber coil.

1C is a spectrogram of the microfiber coupling structure of FIG. 1A. Referring to FIG. 1C, in the present embodiment, the micro-fiber coil resonant cavity will form a transverse electric and magnetic modes (TEM) (as shown in FIG. 1C). Further, as shown in FIG. 1C, the resonance dip value at a wavelength of 1549.999 nm is relatively small, and its full width half maximum is 1.6 picometers (pm). In this embodiment, the quality factor is calculated by dividing the wavelength by its full width at half maximum. In other words, in the present embodiment, the quality factor can be as high as 97,000, which is advantageous for applications in the fields of laser systems, fiber sensing, and nonlinear optics.

In the above embodiment, the number of the first micro-fiber coils 121 is two, and the number of the second micro-fiber coils 131 is one, but the invention is not limited thereto. The following will be further described in conjunction with Figure 2 for possible variations in the number of microfiber coils.

2 is a schematic diagram of a micro-fiber coupling structure according to another embodiment of the present invention. Referring to FIG. 2, in the present embodiment, the microfiber coupling structure 300 of FIG. 2 is similar to the microfiber coupling structure 100 of FIG. 1A, and the differences are as follows. Specifically, as shown in FIG. 2, in the present embodiment, the number of the first micro-fiber coils 121 is three, and the number of the second micro-fiber coils 131 is two. In this way, the micro-fiber coil resonant cavity formed by the micro-fiber coupling structure 300 can also increase the coupling degree between the micro-fiber coils by the first micro-fiber coil 121 and the second micro-fiber coil 131 that are in contact with each other, thereby increasing The probability of leaving light in the cavity of the micro-fiber coil and thereby improving the quality factor of the cavity of the micro-fiber coil. For example, in this embodiment, the quality factor can also be on the order of 10 ⁶ , which is advantageous for applications in the fields of laser systems, fiber sensing, and nonlinear optics.

In summary, the micro-fiber coil resonant cavity formed by the micro-fiber coupling structure of the present invention can be made by the first micro-fiber coil of the first micro-fiber structure layer and the second micro-fiber coil of the second micro-fiber structure layer Coupling to increase the probability of leaving light in the cavity of the microfiber coil and thereby improving the quality factor of the cavity of the microfiber coil.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

100‧‧‧Microfiber coupling structure

110‧‧‧ rod body

120‧‧‧First micro-fiber structure layer

121‧‧‧First micro fiber coil

130‧‧‧Second micro-fiber structure layer

131‧‧‧Second micro fiber coil

MF‧‧‧Microfiber

Claims (6)

A micro-fiber coupling structure comprising: a rod; and a micro-fiber wound on the rod to form a first micro-fiber structure layer and a second micro-fiber structure layer, wherein the first micro-fiber structure layer Surrounding the rod body, and comprising a plurality of first micro-fiber coils, the second micro-fiber structure layer surrounding the first micro-fiber structure layer, and including at least one second micro-fiber coil, and the first micro-fiber coils and The at least one second microfiber coil is coupled to each other to form a microfiber coil resonant cavity. The micro-fiber coupling structure of claim 1, wherein the number of the first micro-fiber coils is two, and the number of the at least one second micro-fiber coil is one. The micro-fiber coupling structure of claim 1, wherein the number of the first micro-fiber coils is three, and the number of the at least one second micro-fiber coils is two. The micro-fiber coupling structure of claim 1, wherein the first micro-fiber coils and the at least one second micro-fiber coils are in contact with each other. The micro-fiber coupling structure according to claim 1, wherein the rod body has an extending direction, the micro-fiber is wound on the rod body in a winding direction, and an angle between the winding direction and the extending direction is falling. Between 85 degrees and 95 degrees. The microfiber coupling structure of claim 1, wherein the microfiber has a diameter length ranging from 1 micrometer to 5 micrometers.