Optical path system of high vacuum low temperature atomic force microscope below 4.2k

Abstract

The present application relates to a kind of 4.2K below high vacuum cryogenic atomic force microscope optical path system, the system includes fiber laser collimation optical path system, two sets of optical lever-laser light path XY moving axis body, optical lever structure cage, four quadrant detector.Two sets of the mounting hole total are equipped on the optical lever-laser light path XY moving axis body, wherein the mounting hole total of one of the optical lever-laser light path XY moving axis body is inserted with the fiber laser collimation optical path system, the mounting hole total of another of the optical lever-laser light path XY moving axis body is inserted with the four quadrant detector;The two sides of the optical lever structure cage are connected with the optical lever-laser light path XY moving axis body respectively, and the lower part of the optical lever structure cage is equipped with probe holder, and the upper part is equipped with metal mirror.The present application realizes the convenient use of atomic force microscope under vacuum and low temperature conditions.

Description

Technical Field

[0001] The present invention relates to the field of extremely low temperature physical property measurement, and in particular to an optical path system of a high vacuum and low temperature atomic force microscope below 4.2K. Background Art

[0002] Currently, surface topography testing under low-temperature and high-vacuum conditions is typically only possible with small scanning tunneling microscopes or small horizontal atomic force microscopes. Existing scanning tunneling microscopes can only detect surface tunneling currents, thereby obtaining surface topography. Small horizontal atomic force microscopes, due to their sample stage design, are limited to testing at 10K. This often precludes multi-scale testing under multiple conditions (optical, electrical, and magnetic).

[0003] With the continuous development of science and technology, the demand for detecting or testing material properties is becoming increasingly urgent, especially in extremely low temperature environments below 4.2K. However, there is currently no corresponding equipment to achieve this. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an easy-to-use high-vacuum and low-temperature atomic force microscope optical path system below 4.2K.

[0005] To solve the above problems, the present invention describes a high vacuum and low temperature atomic force microscope optical path system below 4.2K, characterized in that: the system includes a fiber laser collimation optical path system, two sets of optical lever-laser optical path XY movable axis bodies, an optical lever structure cage, and a four-quadrant detector; both sets of the optical lever-laser optical path XY movable axis bodies are provided with mounting holes, the fiber laser collimation optical path system is inserted into the mounting holes of one set of the optical lever-laser optical path XY movable axis bodies, and the four-quadrant detector is inserted into the mounting holes of the other set of the optical lever-laser optical path XY movable axis bodies; the two sides of the optical lever structure cage are respectively connected to the optical lever-laser optical path XY movable axis bodies, a probe holder is provided at the bottom of the optical lever structure cage, and a metal reflector is provided at the top.

[0006] The fiber laser collimation optical path system includes an FC125um optical fiber, a collimating lens and a focusing lens.

[0007] The optical lever-laser optical path XY movable axis body comprises an optical lever moving mechanism body, a piezoelectric rotary actuator, and an XY movable axis inner core. The XY movable axis inner core is provided at the center of the optical lever moving mechanism body, and a mounting bracket is provided at the top. One side is connected to the optical lever structure cage by a nut, and the surface is connected to the optical lever moving module housing by screws. A hollow shaft is provided at the center of the XY movable axis inner core, into which the fiber laser collimation optical path system and the four-quadrant sensor mounting posts of the four-quadrant detector are respectively inserted. A groove is provided on one side surface of the XY movable axis inner core, and a supporting ball is provided in the groove. A mounting hole I is provided along the circumference of the XY movable axis inner core, and a spring I is provided in this mounting hole I. One end of the spring I is fixed to the optical lever moving mechanism body. The top of the mounting bracket is connected to the piezoelectric rotary actuator. A mounting hole II is provided on the surface of the optical lever moving module housing, and a sliding limit rod is fixed in this mounting hole II. The sliding limit rod passes through a sliding block and is installed in a mounting hole III on the optical lever moving mechanism body.

[0008] The number of the supporting balls and the number of the sliding limiting rods are respectively 4.

[0009] The supporting ball is composed of a spring II fixed on the groove and a ball connected to the spring II.

[0010] Both sides of the optical lever structure cage are connected to the optical lever-laser light path XY moving axis body through nuts respectively.

[0011] The optical lever structure cage includes side panels, a top panel, a back panel and a bottom panel; the side panels are vertically connected to the two sides of the bottom panel, the back panel is vertically connected to the back panel, and a dovetail groove is provided on the front side, which is connected to the probe holder through a spring clip; screw holes are provided on the side panels, and are connected to the optical lever moving mechanism body in the optical lever-laser optical path XY moving axis body through nuts; a laser reflector bracket and a spring bracket are respectively provided on the back panel, and one end of the spring bracket is fixed to the bottom panel; a metal reflector is bonded to the laser reflector bracket by UHV glue; the top panel is provided on the top of the side panel, and the side panel is connected to the optical lever moving mechanism body in the optical lever-laser optical path XY moving axis body.

[0012] An optical observation port is provided on the top plate.

[0013] The side plate is provided with an installation positioning port, which is connected to the optical lever moving mechanism body in the optical lever-laser optical path XY moving axis body.

[0014] The four-quadrant detector includes a four-quadrant sensor and a four-quadrant sensor cable box; the four-quadrant sensor cable box is connected to a four-quadrant sensor mounting column via screws, and the four-quadrant sensor mounting column is connected to the four-quadrant sensor; the four-quadrant sensor mounting column is connected to the inner core of the XY moving axis in the optical lever-laser optical path XY moving axis body.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] 1. In the present invention, a metal reflector is provided on the upper part of the cage of the optical lever structure, and conventional optical elements such as dichroic mirrors, polarization beam splitters and quarter-wave plates that cannot be used in vacuum and low temperature are not used.

[0017] 2. The present invention is provided with a fiber laser collimation optical path system comprising an FC125um optical fiber, a collimating lens and a focusing lens. During use, lasers of different energies and properties can be replaced at any time as needed.

[0018] 3. The optical lever-laser optical path XY moving axis body in the present invention, the XY moving mechanism can be compatible with the use of four-quadrant detectors and fiber laser collimation optical path systems.

[0019] 4. The present invention is based on 1.5K and 10 -9 The fully automatic optical path optimization design under the atomic force microscope used in the environment of Pa has realized the convenient use of the atomic force microscope under vacuum and low temperature conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0021] Figure 1 It is a structural schematic diagram of the present invention.

[0022] Figure 2 Schematic diagram of the optical lever-laser optical path XY moving axis body in the present invention.

[0023] Figure 3 Schematic diagram of the optical lever structure cage in the present invention.

[0024] Figure 4 Schematic diagram of the four-quadrant detector described in the present invention.

[0025] In the figure: 1—fiber laser collimation optical path system; 2—optical lever-laser optical path XY moving axis body; 201—support ball; 202—sliding block; 203—optical lever moving module housing; 204—spring I; 205—sliding limit rod; 206—optical lever moving mechanism body; 207—mounting frame; 208—piezoelectric rotation actuator; 209—XY moving axis inner core; 3—optical lever structure cage; 301—side plate; 302—top plate; 303—back plate; 304—laser reflector bracket; 305—spring bracket; 306—bottom plate; 4—probe holder; 5—four-quadrant detector; 501—four-quadrant sensor; 502—four-quadrant sensor mounting column; 503—four-quadrant sensor cable box. DETAILED DESCRIPTION

[0026] like Figures 1 to 4 As shown, a sub-4.2K high-vacuum, low-temperature atomic force microscope optical system comprises a fiber laser collimation optical system 1, two sets of optical lever-laser optical path XY movable axis bodies 2, an optical lever structure cage 3, and a four-quadrant detector 5. Both sets of optical lever-laser optical path XY movable axis bodies 2 are provided with mounting holes. The fiber laser collimation optical system 1 is inserted into the mounting hole of one set of optical lever-laser optical path XY movable axis bodies 2, while the four-quadrant detector 5 is inserted into the mounting hole of the other set of optical lever-laser optical path XY movable axis bodies 2. The optical lever structure cage 3 is connected to the optical lever-laser optical path XY movable axis bodies 2 on both sides. A probe holder 4 is provided at the bottom of the optical lever structure cage 3, and a metal reflector is provided at the top.

[0027] The entire system consists of a simple optical system that only uses metal mirrors, without using conventional optical components such as dichroic mirrors, polarization splitters, and quarter-wave plates that cannot be used in vacuum and low temperatures.

[0028] Fiber laser alignment system 1 includes an FC125µm fiber, collimating lens, and focusing lens. It was provided by Blue Sky Research (model: FDRV635-001SA0). This system places the laser source outside the vacuum system and utilizes a CF interface for ease of use. Lasers of varying energies and properties can be readily switched during operation.

[0029] The optical lever-laser optical path XY moving axis body 2 includes an optical lever moving mechanism body 206, a piezoelectric rotary actuator 208 and an XY moving axis inner core 209; the center of the optical lever moving mechanism body 206 is provided with an XY moving axis inner core 209, and a mounting bracket 207 is provided on the top. One side is connected to the optical lever structure cage 3 by a nut, and the surface is connected to the optical lever moving module housing 203 by screws; the center of the XY moving axis inner core 209 is provided with a hollow shaft, and the four-quadrant sensor mounting column 502 in the fiber laser collimation optical path system 1 and the four-quadrant detector 5 are respectively inserted into the hollow shaft; XY A groove is provided on one side surface of the inner core 209 of the movable shaft, and a supporting ball 201 is provided in the groove; a mounting hole I is provided along the circumference of the inner core 209 of the XY movable shaft, and a spring I 204 is provided in the mounting hole I; one end of the spring I 204 is fixed in the optical lever moving mechanism body 206; the top of the mounting frame 207 is connected to the piezoelectric rotation actuator 208; a mounting hole II is provided on the surface of the optical lever moving module housing 203, and a sliding limit rod 205 is fixed in the mounting hole II; the sliding limit rod 205 passes through the sliding block 202 and is installed in the mounting hole III on the optical lever moving mechanism body 206.

[0030] The number of the supporting balls 201 and the number of the sliding limiting rods 205 are four respectively.

[0031] The supporting ball 201 is composed of a spring II fixed on the groove and a ball connected to the spring II.

[0032] Both sides of the optical lever structure cage 3 are connected to the optical lever-laser light path XY moving axis body 2 through nuts.

[0033] The universal XY movement mechanism, consisting of a support ball 201, a sliding block 202, an optical lever movement module housing 203, a spring I 204, a sliding limit rod 205, an optical lever movement mechanism body 206, a mounting bracket 207, a piezoelectric rotary actuator 208, and an XY movement axis inner core 209, is compatible with both the four-quadrant detector 5 and the fiber laser alignment optical path system 1. The use of the piezoelectric rotary actuator 208 also allows for fully automatic and simple adjustment of the optical system.

[0034] The optical lever structure cage 3 includes side panels 301, a top panel 302, a back panel 303 and a bottom panel 306; the bottom panel 306 is vertically connected to the side panels 301 on both sides, the back panel 303 on the rear side, and a dovetail groove on the front side, which is connected to the probe holder 4 through a spring clip; screw holes are provided on the side panels 301, and are connected to the optical lever moving mechanism body 206 in the optical lever-laser optical path XY moving axis body 2 through nuts; a laser reflector bracket 304 and a spring bracket 305 are respectively provided on the back panel 303, one end of the spring bracket 305 is fixed to the bottom panel 306; a metal reflector is bonded to the laser reflector bracket 304 by UHV glue; a top panel 302 is provided on the top of the side panel 301, and the side panel 301 is connected to the optical lever moving mechanism body 206 in the optical lever-laser optical path XY moving axis body 2.

[0035] An optical observation port is provided on the top plate 302. An installation positioning port is provided on the side plate 301, and the installation positioning port is connected to the optical lever moving mechanism body 206 in the optical lever-laser optical path XY moving axis body 2.

[0036] The four-quadrant detector 5 includes a four-quadrant sensor 501 and a four-quadrant sensor cable box 503; the four-quadrant sensor cable box 503 is connected to a four-quadrant sensor mounting column 502 by screws, and the four-quadrant sensor mounting column 502 is connected to the four-quadrant sensor 501; the four-quadrant sensor mounting column 502 is connected to the XY moving axis inner core 209 in the optical lever-laser light path XY moving axis body 2.

[0037] The probe holder 4 is inserted into the lower part of the optical lever structure cage 3 through a spring buckle.

[0038] The manufacturer of the piezoelectric rotary actuator 208 is Newport, and the model number is Picomotor.

[0039] UHV glue is provided by Agilent, model: Torr Seal.

[0040] The manufacturer of the four-quadrant sensor 501 is: First Sensor (First Sensor Company), model: QP50-6.

[0041] Working principle of the present invention: The present invention utilizes an integrated fiber optic optical path and a piezoelectric rotary actuator 208 in combination with an optical lever system to amplify the position signal of the atomic force microscope through a four-quadrant sensor 501 to obtain sub-nanometer position resolution.

[0042] When in use, the laser spot is introduced into the optical lever structure cage 3 through the fiber laser collimating optical path system 1, and the optical system optical path adjustment and centering is achieved through the piezoelectric rotary actuator 208.

Claims

1. A high vacuum and low temperature atomic force microscope optical system below 4.2K, characterized by: The system comprises a fiber laser collimating optical path system (1), two sets of optical lever-laser optical path XY movable axis bodies (2), an optical lever structure cage (3), and a four-quadrant detector (5); both sets of the optical lever-laser optical path XY movable axis bodies (2) are provided with mounting holes, the fiber laser collimating optical path system (1) is inserted into the mounting holes of one set of the optical lever-laser optical path XY movable axis bodies (2), and the four-quadrant detector (5) is inserted into the mounting holes of the other set of the optical lever-laser optical path XY movable axis bodies (2); both sides of the optical lever structure cage (3) are respectively connected to the optical lever-laser optical path XY movable axis bodies (2); a probe holder (4) is provided at the bottom of the optical lever structure cage (3), and a metal reflector is provided at the top; The optical lever structure cage (3) comprises side plates (301), a top plate (302), a back plate (303) and a bottom plate (306); the sides of the bottom plate (306) are vertically connected to the side plates (301), the rear side is vertically connected to the back plate (303), and the front side is provided with a dovetail groove, which is connected to the probe holder (4) through a spring buckle; the side plates (301) are provided with screw holes, and are connected to the optical lever moving mechanism body (206) in the optical lever-laser light path XY moving axis body (2) through nuts; the back plate (303) is respectively provided with a laser reflector bracket (304) and a spring bracket (305), one end of the spring bracket (305) is fixed to the bottom plate (306); the laser reflector bracket (304) is connected to the probe holder (4) through a UHV screw. The metal reflector is bonded with glue; the top plate (302) is provided on the top of the side plate (301), and the side plate (301) is connected to the optical lever moving mechanism body (206) in the optical lever-laser light path XY moving axis body (2).

2. The optical path system of a high vacuum and low temperature atomic force microscope below 4.2K according to claim 1, characterized in that: The fiber laser collimation optical path system (1) comprises an FC125um optical fiber, a collimating lens and a focusing lens.

3. The optical path system of a high vacuum and low temperature atomic force microscope below 4.2K according to claim 1, characterized in that: The optical lever-laser optical path XY moving axis body (2) comprises an optical lever moving mechanism body (206), a piezoelectric rotary actuator (208) and an XY moving axis inner core (209); the center of the optical lever moving mechanism body (206) is provided with the XY moving axis inner core (209), the top is provided with a mounting frame (207), one side is connected to the optical lever structure cage (3) through a nut, and the surface is connected to the optical lever moving module housing (203) through screws; the center of the XY moving axis inner core (209) is provided with a hollow shaft, and the fiber laser collimating optical path system (1) and the four-quadrant sensor mounting column (502) in the four-quadrant detector (5) are respectively inserted into the hollow shaft; the XY A groove is provided on one side surface of the inner core (209) of the moving shaft, and a supporting ball (201) is provided in the groove; a mounting hole I is provided along the circumference of the inner core (209) of the XY moving shaft, and a spring I (204) is provided in the mounting hole I; one end of the spring I (204) is fixed in the body (206) of the optical lever moving mechanism; the top of the mounting frame (207) is connected to the piezoelectric rotary actuator (208); a mounting hole II is provided on the surface of the housing (203) of the optical lever moving module, and a sliding limit rod (205) is fixed in the mounting hole II; the sliding limit rod (205) passes through the sliding block (202) and is installed in the mounting hole III on the body (206) of the optical lever moving mechanism.

4. The optical path system of a high vacuum and low temperature atomic force microscope below 4.2K according to claim 3, characterized in that: The number of the supporting balls (201) and the number of the sliding limiting rods (205) are four respectively.

5. The optical path system of a high vacuum and low temperature atomic force microscope at a temperature below 4.2K according to claim 3 or 4, characterized in that: The supporting ball (201) is composed of a spring II fixed on the groove and a ball connected to the spring II.

6. The optical path system of a high vacuum and low temperature atomic force microscope below 4.2K according to claim 1, characterized in that: Both sides of the optical lever structure cage (3) are connected to the optical lever-laser light path XY moving axis body (2) via nuts respectively.

7. The optical path system of a high vacuum and low temperature atomic force microscope below 4.2K according to claim 1, characterized in that: An optical observation port is provided on the top plate (302).

8. The optical path system of a high vacuum and low temperature atomic force microscope below 4.2K according to claim 1, characterized in that: The side plate (301) is provided with an installation positioning opening, which is connected to the optical lever moving mechanism body (206) in the optical lever-laser light path XY moving axis body (2).

9. The optical path system of a high vacuum and low temperature atomic force microscope below 4.2K according to claim 1, characterized in that: The four-quadrant detector (5) comprises a four-quadrant sensor (501) and a four-quadrant sensor cable box (503); the four-quadrant sensor cable box (503) is connected to a four-quadrant sensor mounting post (502) via screws, and the four-quadrant sensor mounting post (502) is connected to the four-quadrant sensor (501); the four-quadrant sensor mounting post (502) is connected to an XY movable axis inner core (209) in the optical lever-laser optical path XY movable axis body (2).

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