CN214427470U - Low-temperature near-field optical microscope based on optical fiber - Google Patents
Low-temperature near-field optical microscope based on optical fiber Download PDFInfo
- Publication number
- CN214427470U CN214427470U CN202023185663.5U CN202023185663U CN214427470U CN 214427470 U CN214427470 U CN 214427470U CN 202023185663 U CN202023185663 U CN 202023185663U CN 214427470 U CN214427470 U CN 214427470U
- Authority
- CN
- China
- Prior art keywords
- optical fiber
- optical
- fiber
- field
- coupler
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Microscoopes, Condenser (AREA)
Abstract
The utility model discloses a low temperature near field optical microscope based on optic fibre for measure the sample, including optics subtotal scanning mechanical part, optics subtotal light source, fiber coupler, interference arm, detector and near field coupling structure, the light source with fiber coupler's first incident port fixed connection, the detector with fiber coupler's second incident port fixed connection. The utility model discloses a low temperature near field optical microscope based on optic fibre, its debugging calibration process that has not only saved light beam guiding mechanism has still avoided the position drift influence that system mechanical parts is ageing to be brought, and it has better anti environmental disturbance ability, mounted position receive the actual installation environment influence little and can be more economic advantage such as ultra-low temperature environment that reaches 1.2K, 4K.
Description
Technical Field
The utility model belongs to the technical field of scanning near field optical microscope, concretely relates to low temperature near field optical microscope based on optic fibre.
Background
A scanning near-field optical microscope (SNOM) is an optical imaging scheme which breaks through the diffraction limit of a conventional optical microscope, and can realize synchronous and accurate measurement of key properties such as appearance, components, mechanics and the like of a sample material under the nanoscale. Meanwhile, due to the non-contact detection principle, the nondestructive measurement can be realized on the sample, so that the method has greater advantages in the field of biological materials.
The existing SNOM system is mainly composed of two parts, an optical part for restricting an optical beam and detecting and analyzing and a scanning mechanical part for controlling a sample and a probe. The scanning mechanical part is an Atomic Force Microscope (AFM), the mature AFM can be directly adopted, and a system with the same function is specifically designed according to the AFM principle in special application. The optical part is usually composed of a light beam guiding mechanism designed based on the Michelson interferometer principle, and a control motor, a light beam detector and a signal amplifying and demodulating device required by interferometry are attached. However, the optical beam guided by the optical beam guiding mechanism built by the michelson interferometer principle is located in a free space, and the accuracy requirement is very high due to the scanning probe size, and each optical beam deflection element is often required to have an adjusting function, otherwise, the optical beam cannot be successfully guided to a specified area. The presence of a large number of optical element mounts presents two problems: firstly, the optical element adjusting frame occupies a large space, the whole mechanism is limited by the overall dimension of the adjusting frame, and any mechanical adjusting frame has the phenomenon that a moving mechanism ages along with time more or less, so that the adjusted optical beam can deviate and lose the original function after a period of time; secondly, a window must be opened for the introduction of free space light in the cryogenic system, which may cause temperature increase due to external radiation.
To the problem that current SNOM system exists, the utility model provides a low temperature near field optical microscope based on optic fibre with SNOM optical beam guiding mechanism of full fiberization.
SUMMERY OF THE UTILITY MODEL
The utility model discloses a main aim at provides low temperature near field optical microscope based on optic fibre, its debugging calibration process that has not only saved light beam guiding mechanism has still avoided the position drift influence that system's mechanical parts is ageing to be brought, and it has better anti environmental disturbance ability, mounted position receive the actual installation environment influence little and can be more economic advantage such as ultra-low temperature environment that reaches 1.2K, 4K.
Another object of the present invention is to provide a low temperature near field optical microscope based on optical fiber for measuring samples, including optical part and scanning mechanical part, the optical part includes light source, fiber coupler, interference arm, detector and near field coupling structure, wherein:
the light source is fixedly connected with a first incident port of the optical fiber coupler, and the detector is fixedly connected with a second incident port of the optical fiber coupler;
the first exit port of optical fiber coupler with near field coupling structure fixed connection, near field coupling structure be used for with the light beam of light source transmission assembles in scanning mechanical part's scanning probe's (probe) effective near field scattering region on the needle point (the utility model discloses a scattering formula near field microscope's scanning probe's structure is cantilever beam, probe, has metal coating film on probe and the cantilever beam) and collects sample near field information, optical fiber coupler's second exit port with interfere arm fixed connection.
The near-field scattered light beam (collected sample near-field information) collected by the near-field coupling structure returns to the optical fiber coupler, wherein high proportion of energy enters the detector, low proportion of energy enters the optical fiber isolator to be blocked, the included angle between the main optical axis of the near-field coupling structure and the surface of the sample is 30 degrees, and the whole structure is fixed on a three-dimensional displacement platform driven by a piezoelectric stepping motor so as to realize accurate coupling with the needle tip of the scanning probe.
The first exit port is used for outputting a low-power signal when being opposite to the first incident port, and the first exit port is used for outputting a high-power signal when being opposite to the second incident port;
the second exit port is a low-power signal output when corresponding to the second incident port, and the second exit port is a high-power signal output when corresponding to the first incident port.
The optical fiber coupler is a 2x2 optical fiber branching unit, the optical fiber branching unit selected by the utility model is bidirectional transmission and has an energy distribution ratio of 9:1, and the optical fiber coupler can divide the light beam incident from any port according to the energy ratio of 9:1 and then is emitted from two output ports.
As a further preferable technical solution of the above technical solution, the light source includes a laser and an optical fiber isolator, the optical fiber isolator is fixedly connected to the first incident port of the optical fiber coupler, and one end of the optical fiber isolator, which is far away from the optical fiber coupler, is fixedly connected to the laser (the laser is used as a system light source, and parameters such as wavelength and power of the laser are determined by a sample under study).
As a further preferable technical solution of the above technical solution, the laser includes a laser source, an optical lens group, a first optical fiber, a first fixing structure, and a driving control circuit, the laser source, the optical lens group, and the first optical fiber are all mounted in the first fixing structure, the optical lens group is mounted between the laser source and the first optical fiber, and the first optical fiber is connected to one end of the optical fiber isolator close to the laser.
As a further preferable technical solution of the above technical solution, the interference arm includes an optical fiber stretcher driven by piezoelectric ceramics and a second optical fiber having a tail end provided with a reverse coupler, the second optical fiber is wound and fixed on the optical fiber stretcher, one end of the second optical fiber, which is far away from the reverse coupler, is fixedly connected to a second exit port of the optical fiber coupler, the reverse coupler can reversely transmit the extremely low-loss optical beam in the second optical fiber to the optical fiber coupler, wherein high-proportion energy enters the optical fiber isolator to be blocked, low-proportion energy enters the detector, and the optical fiber stretcher is driven by the piezoelectric ceramics to enable the optical fiber to realize expansion change of several hundred nanometers at a frequency of hundred hertz level, so as to cause a change in optical path of the optical beam in the second optical fiber, thereby realizing an improvement in signal-to-noise ratio of interference measurement signals.
As a further preferable technical solution of the above technical solution, the near-field coupling structure includes a transmission fiber, a collimating lens, a coupling lens, and a second fixing structure, the transmission fiber, the collimating lens, and the coupling lens are all mounted in the second fixing structure, the collimating lens is mounted between the transmission fiber and the coupling lens, and the transmission fiber is connected to the first exit port.
The part of the transmitted light close to the collimating lens is a vitrified fiber head or a ceramic fiber head so as to facilitate structure fixing and alignment packaging, the collimating lens is a middle and long-focus aspheric lens with a focal length range of 18-40mm, and the coupling lens is a short-focus aspheric lens with a focal length range of 7-15 mm.
Drawings
Fig. 1 is a schematic structural diagram of the low-temperature near-field optical microscope based on optical fiber according to the present invention.
Fig. 2 is a schematic structural diagram of the laser of the low-temperature near-field optical microscope based on optical fiber according to the present invention.
Fig. 3 is a schematic structural diagram of the near-field coupling structure of the low-temperature near-field optical microscope based on optical fiber according to the present invention.
The reference numerals include: 10. a light source; 11. a laser; 111. a laser source; 112. an optical lens group; 113. a first fixed structure; 114. a first optical fiber; 12. a fiber isolator; 20. a fiber coupler; 30. an interference arm; 31. an optical fiber stretcher; 32. a second optical fiber; 33. a reverse coupler; 40. a detector; 50. a near-field coupling structure; 51. a transmission optical fiber; 52. a collimating lens; 53. a coupling lens; 54. a second fixed structure; 60. the probe is scanned.
Detailed Description
The following description is presented to disclose the invention so as to enable any person skilled in the art to practice the invention. The preferred embodiments in the following description are given by way of example only, and other obvious variations will occur to those skilled in the art. The basic principles of the invention, as defined in the following description, may be applied to other embodiments, variations, modifications, equivalents and other technical solutions without departing from the spirit and scope of the invention.
Referring to fig. 1 of the drawings, fig. 1 is a schematic structural diagram of a low-temperature near-field optical microscope based on optical fiber according to the present invention, fig. 2 is a schematic structural diagram of a laser of a low-temperature near-field optical microscope based on optical fiber according to the present invention, and fig. 3 is a schematic structural diagram of a near-field coupling structure of a low-temperature near-field optical microscope based on optical fiber according to the present invention.
In the preferred embodiment of the present invention, it should be noted by those skilled in the art that the scanning mechanism and the sample, etc. related to the present invention can be regarded as the prior art.
Preferred embodiments.
The utility model discloses a low temperature near field optical microscope based on optic fibre for measure the sample, including optical part and scanning mechanical part, its characterized in that, optical part include light source 10, fiber coupler 20, interfere arm 30, detector 40 and near field coupling structure 50, wherein:
the light source 10 is fixedly connected with a first incident port of the optical fiber coupler 20, and the detector 40 is fixedly connected with a second incident port of the optical fiber coupler 20;
the first exit port of the optical fiber coupler 20 is fixedly connected to the near-field coupling structure 50, the near-field coupling structure 50 is used for converging the light beam emitted by the light source 10 into an effective near-field scattering region on the (probe) tip of the scanning probe 60 of the scanning mechanical part (the structure of the scanning probe 60 of the scattering type near-field microscope of the present invention is a cantilever beam, a probe, a metal coating exists on the probe and the cantilever beam) and collecting the near-field information of the sample, and the second exit port of the optical fiber coupler 20 is fixedly connected to the interference arm 30.
The near-field scattered light beam (collected sample near-field information) collected by the near-field coupling structure 50 returns to the optical fiber coupler 20, wherein high proportion of energy enters the detector 40, low proportion of energy enters the optical fiber isolator 12 and is blocked, the included angle between the main optical axis of the near-field coupling structure 50 and the surface of the sample is 30 degrees, and the whole structure is fixed on a three-dimensional displacement table driven by a piezoelectric stepping motor so as to realize accurate coupling with the tip of the scanning probe 60.
The first exit port is used for outputting a low-power signal when being opposite to the first incident port, and the first exit port is used for outputting a high-power signal when being opposite to the second incident port;
the second exit port is a low-power signal output when corresponding to the second incident port, and the second exit port is a high-power signal output when corresponding to the first incident port.
The optical fiber coupler 20 is a 2x2 optical fiber splitter, the optical fiber splitter selected by the utility model is bidirectional transmission and has an energy distribution ratio of 9:1, and the optical fiber splitter can divide the light beam incident from any port according to the energy ratio of 9:1 and then is emitted from two output ports.
Specifically, the light source 10 includes a laser 11 (preferably, a single-mode fiber coupled laser) and a fiber isolator 12, where the fiber isolator 12 is fixedly connected to a first incident port of the fiber coupler 20, and one end of the fiber isolator 12, which is far away from the fiber coupler 20, is fixedly connected to the laser 11 (the laser 11 is used as a system light source, and parameters such as a wavelength and a power of the laser are determined by a sample under study).
More specifically, the laser 11 includes a laser source 111, an optical lens group 112, a first optical fiber 114, a first fixing structure 113, and a driving control circuit, where the laser source 111, the optical lens group 112, and the first optical fiber 114 are all mounted on the first fixing structure 113, the optical lens group 112 is mounted between the laser source 111 and the first optical fiber 114, and the first optical fiber 114 is connected to one end of the optical fiber isolator 12 close to the laser 11.
The laser source 111 is a free space output, and an output light beam thereof is coupled into the system by coupling the light beam emitted by the laser source 111 into a single mode fiber by using the optical lens assembly 112 to form the laser 11.
Further, the interference arm 30 includes an optical fiber stretcher 31 driven by piezoelectric ceramics and a second optical fiber 32 with a reverse coupler 33 mounted at a tail end, the second optical fiber 32 is wound and fixed on the optical fiber stretcher 31, an end of the second optical fiber 32 away from the reverse coupler 33 is fixedly connected with a second exit port of the optical fiber coupler 20, the reverse coupler 33 can transmit the light wave beam in the second optical fiber 32 in a low-loss reverse direction to the optical fiber coupler 20, wherein a high proportion of energy enters the optical fiber isolator 12 to be blocked, a low proportion of energy enters the detector 40, and the optical fiber stretcher 31 can enable the optical fiber to realize expansion change of several hundred nanometers at a frequency of hundred hertz level through the piezoelectric ceramics driving, so that the optical path of the light wave beam in the second optical fiber 32 is changed to realize signal-to-noise ratio improvement of interference measurement.
Furthermore, the near-field coupling structure 50 includes a transmission fiber 51, a collimating lens 52, a coupling lens 53 and a second fixing structure 54, the transmission fiber 51, the collimating lens 52 and the coupling lens 53 are all mounted on the second fixing structure 54, the collimating lens 52 is mounted between the transmission fiber 51 and the coupling lens 53, and the transmission fiber 51 is connected to the first exit port.
Preferably, the portion of the transmission fiber 51 near the collimating lens is a vitrified or ceramic fiber tip for structural fixation and alignment packaging, the collimating lens is a mid-long focus aspheric lens with a focal length in the range of 18-40mm, preferably 18.4mm, and the coupling lens is a short focus aspheric lens with a focal length in the range of 7-15mm, preferably 8 mm.
Preferably, the interface of the optical fiber related to the present invention is FC/APC specification, and is connected by FC/APC optical fiber flange.
Preferably, the utility model discloses an optical part (being light beam guide mechanism) can also adopt the michelson interferometer principle that the light beam is located the free space to build the mechanism, and the light beam that will directly introduce originally to sample scanning probe couples into optic fibre earlier, then conducts to sample scanning probe and carries out the optical coupling through optic fibre, and it expresses as to pass through the product of lens group (being similar to optical lens group 112) the coupling into first optic fibre with the light beam that assembles scanning probe in the free space light path originally, and first optic fibre links to each other with the one end that near field coupling structure 50 kept away from collimation/convergent lens.
The scheme of changing the near-field coupling part of the system into optical fiber transmission can also effectively relieve the complexity of the ultralow temperature system.
It should be noted that the technical features such as the scanning mechanical part and the sample related to the present invention should be regarded as the prior art, and the specific structure, the operation principle, the control mode and the spatial arrangement mode of these technical features may be selected conventionally in the field, which should not be regarded as the invention point of the present invention, and the present invention is not further specifically described in detail.
It will be apparent to those skilled in the art that modifications and variations can be made in the above-described embodiments, or some features of the invention may be substituted or omitted, and any modification, substitution, or improvement made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.
Claims (5)
1. An optical fiber-based cryogenic near-field optical microscope for measuring a sample, comprising an optical portion and a scanning mechanism portion, wherein the optical portion comprises a light source, a fiber coupler, an interference arm, a detector and a near-field coupling structure, wherein:
the light source is fixedly connected with a first incident port of the optical fiber coupler, and the detector is fixedly connected with a second incident port of the optical fiber coupler;
the first exit port of the optical fiber coupler is fixedly connected with the near-field coupling structure, the near-field coupling structure is used for converging the light beam emitted by the light source on an effective near-field scattering region on a needle point of a scanning probe of the scanning mechanical part and collecting near-field information of a sample, and the second exit port of the optical fiber coupler is fixedly connected with the interference arm.
2. The optical fiber-based cryogenic near-field optical microscope of claim 1, wherein the optical source comprises a laser and a fiber isolator, the fiber isolator is fixedly connected to the first incident port of the fiber coupler, and an end of the fiber isolator away from the fiber coupler is fixedly connected to the laser.
3. The optical fiber-based cryogenic near-field optical microscope of claim 2, wherein the laser comprises a laser source, an optical lens group, a first optical fiber, a first fixing structure and a driving control circuit, the laser source, the optical lens group and the first optical fiber are all mounted on the first fixing structure, the optical lens group is mounted between the laser source and the first optical fiber, and the first optical fiber is connected with one end of the optical fiber isolator near the laser.
4. The optical fiber-based low-temperature near-field optical microscope according to claim 3, wherein the interference arm comprises a fiber stretcher driven by piezoelectric ceramics and a second optical fiber with a back coupler mounted at the end, the second optical fiber is wound and fixed on the fiber stretcher, and the end of the second optical fiber far away from the back coupler is fixedly connected with the second exit port of the fiber coupler.
5. The optical fiber-based cryogenic near-field optical microscope of claim 3, wherein the near-field coupling structure comprises a transmission fiber, a collimating lens, a coupling lens and a second fixed structure, the transmission fiber, the collimating lens and the coupling lens are all mounted on the second fixed structure, the collimating lens is mounted between the transmission fiber and the coupling lens, and the transmission fiber is connected with the first exit port.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202023185663.5U CN214427470U (en) | 2020-12-26 | 2020-12-26 | Low-temperature near-field optical microscope based on optical fiber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202023185663.5U CN214427470U (en) | 2020-12-26 | 2020-12-26 | Low-temperature near-field optical microscope based on optical fiber |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN214427470U true CN214427470U (en) | 2021-10-19 |
Family
ID=78053123
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202023185663.5U Active CN214427470U (en) | 2020-12-26 | 2020-12-26 | Low-temperature near-field optical microscope based on optical fiber |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN214427470U (en) |
-
2020
- 2020-12-26 CN CN202023185663.5U patent/CN214427470U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6330063B1 (en) | Low coherence interferometer apparatus | |
| US5712705A (en) | Arrangement for analysis of substances at the surface of an optical sensor | |
| US5445011A (en) | Scanning force microscope using an optical trap | |
| EP0546071B1 (en) | Interference microscope | |
| CN104006891B (en) | Nanoscale light field phase distribution measuring instrument | |
| US5017010A (en) | High sensitivity position sensor and method | |
| JP5540017B2 (en) | Optical imaging for optical device inspection | |
| CN106323907A (en) | Optical fiber coupling terahertz time-domain spectroscopy testing system | |
| CN103529243A (en) | Light beam tracking type atomic force microscope scanning measuring head | |
| KR20060124786A (en) | Optical fiber probe, optical detection device, and optical detection method | |
| CN111060719A (en) | Terahertz pulse beam extraction mechanism of terahertz near-field microscope | |
| CN112595860A (en) | Low-temperature near-field optical microscope based on optical fiber | |
| US5375011A (en) | Non-linear, real-time, micrometer resolution optical time domain reflectometers for optoelectronic circuits diagnostic and sensing applications | |
| CN214427470U (en) | Low-temperature near-field optical microscope based on optical fiber | |
| KR920704173A (en) | Near field reflection microscope operation method and microscope | |
| Butler et al. | Characterization of optical fibers using near‐field scanning optical microscopy | |
| CN110361363B (en) | Resolution compensation device and compensation method for terahertz wave attenuated total reflection imaging | |
| CN100538913C (en) | The sensor that has cantilever and optical resonator | |
| CN113341180B (en) | Multi-mode measurement method and measurement system based on near-field non-hole probe | |
| CN211785622U (en) | Terahertz pulse beam extraction mechanism of terahertz near-field microscope | |
| JPH0712826A (en) | Interferometer, optical scanning tunnel microscope, and optical probe | |
| JPWO2005003737A1 (en) | Photodetection apparatus and method | |
| CN210465257U (en) | Resolution compensation device for terahertz wave attenuation total reflection imaging | |
| US20100229262A1 (en) | Apparatus and method for examining a specimen by means of probe microscopy | |
| CN109443241A (en) | A kind of high speed axial direction scanning confocal micro-measurement apparatus and method based on tuning fork driving |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |