JP2005309028A - Optical fiber connector and sample observation device - Google Patents

Abstract

A problem to be solved by the present invention is that an insertion-side optical fiber connector is connected to a receiving-side optical fiber connector using a magnet loader or the like in an environment where direct operation cannot be performed by a human hand such as in an ultra-high vacuum. In the case of connection, it is difficult to connect because sufficient alignment accuracy is not obtained.
A ferrule that performs terminal processing of an optical fiber, an insertion guide that is provided around the ferrule, an elastic body that exerts a force in a longitudinal direction and an axial direction on the ferrule, and the elastic body An optical fiber connector, comprising: a housing that accommodates and restricts movement of the ferrule, wherein at least the ferrule is axially displaceable.
[Selection] Figure 1

Description

  The present invention relates to an optical fiber connector attached to an end face of an optical fiber and a sample observation device for observing an airtight sample.

  In recent years, by bringing the probe close to the surface of a sample such as a metal, semiconductor, insulator, polymer material or living body, and tracing the sample surface so that the physical quantity generated on the probe and the sample surface is constant, Observation with a scanning probe microscope which is a general term for scanning tunnel microscopes, atomic force microscopes, magnetic force microscopes, friction force microscopes, micro viscoelastic microscopes, surface potential difference microscopes, scanning near-field microscopes and similar devices for measuring physical properties Is important. In particular, a scanning near-field optical microscope that can know the optical properties of a sample by using a probe with a sharpened tip of an optical fiber has attracted attention.

  However, the above-mentioned observation with the scanning near-field microscope is sometimes performed in an ultrahigh vacuum environment, and the measurement unit may be moved to a cryostat or the like for cooling. When the measurement unit to which the cable is connected is moved, there is a risk that the optical fiber cable will not have a sufficient bending radius and may be damaged.

  In addition, when optical fibers in an apparatus or between optical fibers and optical components are optically connected, an optical fiber connector is often used. Conventionally, an optical fiber connector is directly used by a human hand or via a jig. It was assumed that this would be done. However, in an ultra-high vacuum environment, it is not possible to work manually, and the magnet loader installed in the scanning near-field microscope does not provide sufficient alignment accuracy. It was difficult to connect the side optical fiber connector. There is no optical fiber connector that can be used under ultra-high vacuum.

  As a conventional technique, there is an optical fiber connector in which ferrules are not inclined, ferrules are in contact with each other, optical fibers are sufficiently in physical contact, and connection loss is small (for example, Patent Document 1).

JP 2002-131582

  The problem to be solved by the present invention is that when the plug-in side optical fiber connector is connected to the receiving side optical fiber connector using a magnet loader or the like in an environment where the work cannot be directly performed by a human hand such as in an ultra-high vacuum. It is difficult to connect because of insufficient alignment accuracy. In addition, the optical fiber connector can be used under an ultra-high vacuum.

  The invention of claim 1 is a ferrule that performs terminal processing of an optical fiber, an insertion guide that is provided around the ferrule, an elastic body that exerts a force in a longitudinal direction and an axial direction on the ferrule, An optical fiber connector including an elastic body and a housing for restricting movement of the ferrule, wherein at least the ferrule is axially displaceable.

  According to a second aspect of the present invention, there is provided a sleeve that guides the insertion-side optical fiber connector with a backlash in the insertion guide, and a ferrule holding means that has a flange portion and holds the ferrule. The receiving-side optical fiber connector according to claim 1, wherein the elastic body is a taper type coiled spring, and the taper type coiled spring presses the flange portion of the ferrule holding means toward the inside of the housing. It is the receiving side optical fiber connector characterized.

  According to a third aspect of the present invention, there is provided an airtight sample observation chamber, the optical fiber connector according to the first aspect of the invention installed in the sample observation chamber, and the first optical fiber connector. A sample observation apparatus comprising: a remote operation means facing each other, wherein the second optical fiber connector held by the remote operation means is attached to and detached from the first optical fiber connector. is there.

  A fourth aspect of the present invention is the sample observation apparatus according to the fourth aspect, wherein the remote control means is a magnet loader.

  The invention according to claim 5 is the sample observation apparatus according to claim 3 or 4, wherein the sample observation apparatus is a scanning probe microscope that detects a physical quantity acting between a probe and a sample. .

  According to the present invention, since the ferrule holding member and the attached portion thereof are supported by the elastic body, the ferrule holding member and the like are moved by a predetermined amount in the axial direction, and the receiving side optical fiber connector and the insertion side optical fiber connector are mismatched in axis. Absorb and can be easily connected.

  Hereinafter, the present invention will be described in detail according to the best mode for carrying out the invention.

  The configuration of the present invention will be described with reference to FIG. FIG. 1 is a sectional view of a receiving side optical fiber connector. In the housing 6, a ferrule holding member 4 and a spring 7 for holding a ferrule 2 that performs terminal processing of the optical fiber cable 1 are housed. The ferrule 2 is a cylindrical rod-shaped part that supports the optical fiber 1 and is easily broken and thin. The optical fiber is bonded and fixed to the center of the ferrule, and the ferrules are brought into contact with each other to connect the optical fibers with high precision. . The ferrule 2 connecting surface is chamfered and the optical fiber 1 appears. The optical fiber cable 1 is coated with a material that can be used even in a bake such as Teflon (registered trademark), an ultra-high vacuum (hereinafter referred to as “UHV”), and a liquid helium temperature environment. Further, the ferrule holding member 4 is held against the inner surface of the housing 6 by a spring 7. The spring 7 is a tapered chord spring. The spring 7 may be a leaf spring or an elastic body such as rubber. The shape of the spring 7 may be cylindrical, but it is more effective when it is tapered. A sleeve holding member 5 is installed on the upper surface of the ferrule holding member 4, protrudes from an opening of the housing 6, and is locked by a flange portion of the ferrule holding member 4. The sleeve 3 is accommodated inside the sleeve holding member 5 with mechanical backlash. FIG. 12 is a front sectional view and a side view of the sleeve 3. The sleeve 3 has a fitting accuracy of micron order with the insertion side ferrule 9 in FIG. The housing 6, the ferrule holding member 5, the ferrule 2 and the sleeve 3 are made of a hard material such as ceramic or zirconium that does not emit gas even when heated to a high temperature. Thereby, it can be used in a bake, UHV, or liquid helium temperature environment. The inner diameter of the sleeve holding member 5 is made slightly larger than the outer shape of the sleeve 3. Since the upper surface of the sleeve holding member 5 is provided with a claw, the sleeve 3 is held with a slight backlash. The sleeve 3 is fixed to the ferrule 2.

  Moreover, the structure of the insertion side optical fiber connector is demonstrated using FIG. A ferrule 9 that is an end face treatment of the optical fiber 8 is held by a ferrule holding member 10. The optical fiber 8 cable is covered with a material such as Teflon (registered trademark). The ferrule holding member 5, the ferrule 2 and the sleeve 3 are made of a hard material such as ceramic or zirconium which does not emit gas or the like even when heated to a high temperature.

  As above, each part of the configuration of the present invention has been described. Next, the operation will be described. FIG. 4 is a view before the insertion side optical fiber connector 14 and the receiving side optical fiber connector 13 are connected. When the optical fibers 1 and 8 are connected, their centers must be aligned in the micron order, but it is difficult to perform micron-order axis alignment from the outside of the sample observation room using a remote control device such as a magnet loader. Also in FIG. 4, the axis is shifted by about ± 1 mm. When the insertion-side optical fiber connector 14 is moved to the reception-side optical fiber connector 13, the tapered surface formed at the tips of the sleeve holding member 5 and the sleeve 3 of the reception-side optical fiber connector 13 and the insertion-side optical fiber connector 14. The tapered surface formed at the tip engages. Thereby, the force which the members fixed mutually, such as the ferrule holding member 4, the ferrule 2, and the optical fiber 1, move in parallel to the left of an axial direction is added. Since the ferrule holding member 4 and the like are supported by the spring 7, as the insertion-side optical fiber connector 14 is inserted, the ferrule holding member 4 and the like move to the left to absorb shaft misalignment. When optical fibers 1 and 8 are connected, their centers must be aligned with micron order, but the ferrules 2 and 9 which are the terminal treatments are manufactured with micron order, and have sleeves with micron order fitting accuracy. By aligning the outer shapes of the ferrules 2 and 9, as a result, the axes of the optical fibers are aligned on the micron order.

  FIG. 5 is a cross-sectional view after the receiving side optical fiber connector 13 is connected to the insertion side optical fiber connector 14. The center of the housing 6 and the optical fibers 1 and 8 are misaligned. Thus, by using the receiving side optical fiber connector 13 having the spring 7, it is possible to absorb the shaft misalignment of about ± 1 mm by utilizing the deformation of the spring 7. The ferrules 2 and 9 of the receiving side optical fiber connector 13 and the insertion side optical fiber connector 14 are held by the sleeve 3, and the axes are aligned with an accuracy of micron order. Further, the receiving-side ferrule 2 is pushed with a force of about 3N, and the optical fibers 1 and 8 are sufficiently in physical contact.

  The displacement that can be absorbed is due to the taper surface of the sleeve holding member 5 and the opening of the sleeve 3 and the stroke of the spring 7. Therefore, when a large displacement is predicted, the stroke of the taper surface and the spring 7 is increased.

  Further, when heating or cooling is performed after mounting, the shaft may be displaced due to thermal expansion / contraction due to a temperature difference, but it can be similarly absorbed by the spring 7. Since the sleeve 3 is not fixed to anything other than the ferrules 2 and 9, the relative thermal expansion and contraction due to the temperature change of the connecting surfaces of the ferrules 2 and 9 is extremely small, and the axial accuracy of the optical fibers 1 and 8 can be maintained on the order of microns. . If the ferrule 2 and the sleeve 3 are made of the same kind of material, high axial accuracy can be maintained.

  When the insertion-side optical fiber connector 14 is removed, the ferrule holding member 4 and the like of the reception-side optical fiber connector 13 returns to the position before insertion by the restoring force of the spring 7.

  6 and 7 show cases where the tilt angles of the axes of the optical fibers 1 and 8 are shifted. Also in this case, the deviation can be absorbed by the spring 7 as in FIGS.

  The configuration of the present invention will be described with reference to the drawings. FIG. 10 is an external view of a sample observation apparatus using the optical fiber connector according to the present invention. The table 35 is installed via a damper 36, and the sample observation chamber 15 is installed on the upper surface of the table 35. The sample observation chamber 15 is kept airtight, and a magnet loader 24 is connected via a vacuum joint 23. Instead of the magnet loader 24, it may be a remote operation device driven by a motor or the like. In addition, a plurality of vacuum joints 23 are installed in the sample observation chamber 15 and are configured so that devices such as options can be connected. Further, a vacuum pump 37 and a gas cylinder attachment terminal 38 are installed in the sample observation chamber 15 via a pipe 39.

  FIG. 8 is a schematic cross-sectional view of the sample observation chamber 15 in FIG. A loader case 25 is airtightly connected to the vacuum joint 23 installed in the sample observation chamber 15. Outer magnets 26 and 27 are movably attached to the outer periphery of the loader case 25, and inner magnets 28 and 29 are movably attached inside the loader case 25. The outer gnet 26 is attracted to the inner magnet 28 and the outer magnet 27 is attracted to the inner magnet 29 by magnetic force.

  A pipe 31 is fixed to the inner magnet 28, and a clamper base 32 is fixed to the other end of the pipe 31. On the other hand, a shaft 30 is fixed to the inner magnet 29, and the shaft 30 passes through the inside of the pipe 31 and is connected to a clamper lever 33 via a link portion (not shown). The clamper lever 33 and a link portion (not shown) are configured like a magic hand. The insertion-side optical fiber connector 14 is detachably sandwiched between the clamper base 32 and the clamper lever 33.

  On the other hand, the inside of the sample observation chamber 15 accommodates a scanning prolobe microscope cell 22 (hereinafter referred to as “SPM cell”) in a movable manner. Another magnet loader (not shown) is installed in the SPM cell 22 and is configured to freely move in the sample observation chamber 15 by an operation from the outside of the sample observation chamber 15.

  A scanner base 19 is installed in the upper part of the SPM cell 22, and a scanner 18 is installed on the lower surface of the scanner base 19. The scanner 18 is composed of a piezo element, and when a voltage is applied by a power source (not shown), the free end is displaced in a three-dimensional direction at the nano level. At the free end of the scanner 18, a scanning near-field microscope probe 16 is installed. Instead of the scanning near-field microscope probe 16, an optical interference AFM cantilever may be used. A receiving side optical fiber connector 13 is installed on the side surface of the SPM cell 22. The structure of the receiving side optical fiber connector 13 is the same as that of FIG. The optical fiber 20 connected to the receiving side optical fiber connector 13 is connected to the probe 16. A sample stage 21 is installed on the bottom surface of the SPM cell 22, and a sample 17 is detachably mounted on the top surface of the sample stage 21.

  The configuration of each unit in the second embodiment has been described above. Next, the operation will be described. The outer magnets 26 and 27 are arranged with a space therebetween. However, if the outer magnets 26 and 27 are moved in parallel on the left side while maintaining the space, the internal magnets 28 and 29 attracted by the magnet via the loader case 25 also maintain the space. The shaft 30 and the hand part 34 fixed to the internal magnet 28 also move leftward. That is, the insertion-side optical fiber connector 29 moves leftward while being sandwiched by the clamper lever 33. Further, the insertion side optical fiber connector 14 is connected to the receiving side optical fiber connector 13 by moving to the left while maintaining the distance between the outer magnets 26 and 27.

  In this case, since the magnet loader 24 has mechanical backlash, the optical axes of the receiving side optical fiber connector 13 and the insertion side optical fiber connector may be shifted by about ± 1 mm in parallel, or the angle of the optical axis may be shifted. . However, since the receiving side optical fiber connector 13 has a spring, it can absorb the deviation of the optical axis as in the first embodiment.

  After the connection, when the outer magnet 27 is moved to the left without moving the outer magnet 26, the inner magnet 29 and the shaft 30 move in conjunction with each other, and the clamper lever 33 opens like a magic hand. Is opened (FIG. 9).

  Then, the outer magnets 26 and 27 are simultaneously moved to the right standby position. An optical fiber is connected to the SPM cell 22, and measurement is possible.

  When it is desired to move the SPM cell 22 to a cryostat (not shown) for cooling, for example, the same operation is repeated, the insertion side optical fiber connector 14 is removed, and the SPM cell 22 is moved to a measurement position (not shown). . If the SPM cell 22 is moved while the optical fiber is connected, the optical fiber is bent below the allowable bending radius, and more force than the allowable tension is applied to the optical fiber, which may damage the optical fiber. is there. After the movement, measurement is performed by similarly connecting another plug-in optical fiber connector (not shown) using another magnet loader (not shown) at a measurement position (not shown).

It is sectional drawing of the receiving side optical fiber connector by this invention. It is sectional drawing of the insertion side optical fiber connector by this invention. It is sectional drawing after the optical fiber connector by this invention has connected (when the axis is correct). It is sectional drawing when connecting the optical fiber connector by this invention (when the axis | shaft has shifted | deviated in parallel). It is sectional drawing after connecting in FIG. It is sectional drawing when connecting the optical fiber connector by this invention (when the inclination angle of a shaft has shifted | deviated). It is sectional drawing after connecting in FIG. It is sectional drawing of the sample observation apparatus provided with the optical fiber connector by this invention. It is sectional drawing of the sample observation apparatus after connecting the optical fiber connector in FIG. It is an external view of the sample observation apparatus provided with the optical fiber connector by this invention. It is sectional drawing and a side view of a ferrule. It is sectional drawing and a side view of a sleeve. It is the figure which connected the optical fiber connector in a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical fiber 2 Ferrule 3 Sleeve 4 Ferrule holding member 5 Sleeve holding member 6 Housing 7 Tapered spring 8 Optical fiber 9 Ferrule 10 Ferrule holding member 11 Receiving side optical fiber connector attaching part 12 Plug-in side optical fiber connector attaching part 13 Receiving side Optical fiber connector 14 Insertion side optical fiber connector 15 Sample observation room 16 Probe 17 Sample 18 Scanner 19 Scanner base 20 Optical fiber 21 Sample stage 22 SPM cell 23 Vacuum joint 24 Magnet loader 25 Loader case 26 Outer magnet 27 Outer magnet 28 Inside Magnet 29 Inner magnet 30 Shaft 31 Pipe 32 Clamper base 33 Clamper lever 34 Hand part 35 Table 36 Damper 37 Vacuum pump 38 Gas cylinder mounter Naru 39 pipe 40 viewing window

Claims (5)

A ferrule for terminal processing of an optical fiber,
An insertion guide provided around the ferrule;
An elastic body that exerts a force in the longitudinal direction and the axial direction on the ferrule;
A housing that houses the elastic body and restricts movement of the ferrule, and an optical fiber connector comprising:
An optical fiber connector, wherein at least the ferrule is axially displaceable. A sleeve for guiding the insertion side optical fiber connector, inscribed in the insertion guide with play,
A receiving-side optical fiber connector according to claim 1, comprising a ferrule holding means that has a flange portion and holds the ferrule.
The elastic body is a taper type string spring,
A receiving-side optical fiber connector, wherein a flange portion of the ferrule holding means is pressed toward the inside of the housing by the taper type coiled spring. An airtight sample observation room,
The optical fiber connector according to claim 1 or 2 installed in the sample observation chamber;
In a sample observation device comprising a remote control means facing the first optical fiber connector,
A sample observation apparatus, wherein the second optical fiber connector held by the remote control means is attached to and detached from the first optical fiber connector.   The sample observation apparatus according to claim 4, wherein the remote control means is a magnet loader.   5. The sample observation apparatus according to claim 3, wherein the sample observation apparatus is a scanning probe microscope that detects a physical quantity acting between a probe and a sample.

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