SAMPLE HOLDER FOR MEASUREMENTS OF OPTICALLY DETECTED MAGNETIC RESONANCE
20220404444 · 2022-12-22
Assignee
Inventors
Cpc classification
G01R33/323
PHYSICS
G01R33/30
PHYSICS
G01R33/34007
PHYSICS
International classification
Abstract
The invention is related to a sample holder for measurements of optically detected magnetic resonance, including a bottom plate, a top plate and a middle plate, wherein all the plates are made of a dielectric material. The top plate is provided with at least one top opening, enabling continuous optical access to the studied sample during measurements. The sample is placed in the central opening provided in the middle plate. The non-magnetic conductive strips provided on the surfaces of the bottom plate, the middle plate and the top plate ensure formation of an electrical circuit, which allows coupling of the studied sample with the generated microwave radiation to be achieved once the microwave sources is switched on. The invention also includes a sample holder for measurements of optically detected magnetic resonance, enabling formation of at least one loop of the electrical circuit.
Claims
1. A sample holder intended for measurements of optically detected magnetic resonance, including a bottom plate (1) and a top plate (2), characterised in that between the bottom plate (1), made of a dielectric material, and the top plate (2), made of dielectric material, in which at least one top opening (3a . . . 3h) is provided, the middle plate (5) made of a dielectric material is provided, in which the central opening (6) is provided, wherein at least one bottom, conductive non-magnetic strip (7) is provided on the surface of the bottom plate (1) oriented towards the top plate (2), which is connected at its first end with the first pole of the microwave signal carrier, while at its second end it forms an electrical connection with the first end of at least one central, surrounding, conductive non-magnetic strip (8), and wherein at least one central, surrounding, conductive non-magnetic strip (8) is provided on the middle plate (5) from the side of the central opening (6), transversely to the side of the middle plate (5), and wherein at least one central, surrounding, conductive non-magnetic strip (8) is overlapping at its ends with both surfaces of the middle plate (5), while the second end of at least one central, surrounding, conductive non-magnetic strip (8) forms an electrical connection with the first end of at least one top, conductive non-magnetic strip (9), which is provided on the surface of the top plate (2) oriented towards the bottom plate (1), and the second end of at least one top, conductive non-magnetic strip (9) forms electrical connection with the first end of at least one central, surface, conductive non-magnetic strip (10), which is provided on the side of the middle plate (5) opposite to at least one central, surrounding, conductive non-magnetic strip (8), on the surface oriented towards the top plate (2), and wherein the second end of at least one, central, surface, conductive non-magnetic strip (10) is connected with the other pole of the microwave signal carrier, wherein the bottom plate (1), the top plate (2) and the middle plate (5) are detachably connected.
2. A holder according to claim 1, characterised in that the top opening (3a, 3b) is divided by a bridge (4), made of a dielectric material.
3. A holder according to claim 1, characterised in that the top opening (3) is provided on the top plate (2) along the conductive non-magnetic strip (9).
4. A holder according to claim 1, characterised in that the middle plate (5) is made of at least two, separated plates (5a, 5b) made of a dielectric material.
5. A holder according to claim 1 characterised in that the dielectric material is a glass fibre-reinforced epoxy laminate, preferably FR-4.
6. A holder according to claim 1, characterised in that the central opening (6) comprises space for sample placement therein, wherein the sample is placed between the bottom plate (1) and the top plate (2).
7. A holder according to claim 1, characterised in that the bottom, conductive non-magnetic strip (7), the central, surrounding, conductive non-magnetic strip (8), the top, conductive non-magnetic strip (9) and the central, surface, conductive non-magnetic strip (10) are made of metal, such as copper or gold, and are preferably made of gold-plated copper.
8. A holder according to claim 1, characterised in that the bottom plate (1), the top plate (2) and the middle plate (5) are provided with connecting openings (11), through which detachable connections pass through.
9. A holder according to claim 8, characterised in that the detachable connections are provided as screws made of a non-magnetic material.
10. A holder according to claim 1, characterised in that at least one top opening (3) has a rectangular shape.
11. A holder according to claim 1, characterised in that the bottom, conductive non-magnetic strip (7) and the central, surface, conductive non-magnetic strip (10) are connected at one of their ends with the poles of the microwave signal carrier via the microwave socket, preferably a SMP-type socket.
12. A holder according to claim 1, characterised in that the height of the middle plate (5) is bigger than the height of the studied sample.
13. A sample holder for measurements of optically detected magnetic resonance, which includes a bottom plate (1) and a top plate (2), characterised in that between the bottom plate (1), made by a dielectric material, and the top plate (2), made of a dielectric material, in which a top opening (3a) is provided, a middle plate (5) made of a dielectric material is provided, in which the central opening (6) is provided, and wherein conductive non-magnetic strips are provided on the bottom plate (1), the middle plate (5) and the top plate (2), which connect and form at least one loop of an electrical circuit.
14. A holder according to claim 13, characterised in that the dielectric material is a glass fibre-reinforced epoxy laminate, preferably FR-4.
15. A holder according to claim 13, characterised in that the middle plate (5) is made of at least two separated parts made of a dielectric material.
16. A holder according to claim 13, characterised in that the conductive non-magnetic strips are made of metal, such as copper or gold, preferably of gold-plated copper.
17. A holder according to claim 13, characterised in that the bottom plate (1), the top plate (2) and the middle plate (5) are provided with connecting openings (11), through which detachable connections pass through.
18. A holder according to claim 17, characterised in that the detachable connection is provided as screws made of a non-magnetic material.
19. A holder according to claim 13, characterised in that the top opening (3a) has a rectangular shape.
20. A holder according to claim 13, characterised in that the height of the middle plate (5) is bigger than the height of the studied sample.
21. A holder according to claim 13, characterised in that at least one loop of the electrical circuit is terminated with a microwave socket, preferably a SMP-type socket.
Description
[0013] The sample holder for measurements of optically detected magnetic resonance is presented in embodiments of the invention and in the figures, in which:
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EXAMPLE EMBODIMENT 1
[0057] In the first embodiment of the invention a sample holder is provided for measurements of optically detected magnetic resonance, which includes the bottom plate 1, the top plate 2 and the middle plate 5, wherein the bottom plate 1 has dimensions 25 mm×60 mm×1 mm, the top plate 2 has dimensions 25 mm×45 mm×1 mm, while the middle plate has dimensions 25 mm×55 mm×0.5 mm. The middle plate 5 is provided with a rectangular, central opening 6, which has dimensions 16 mm×20 mm×0.5 mm. In the top plate 2, the top opening is formed by two rectangular, top openings 3a and 3b, divided symmetrically along the longer side of the top plate 2 by a bridge 4, also made of FR-4, with a width of 1 mm. Connecting openings 11 with a 1.5 mm diameter are provided coaxially in all three plates, wherein brass screws with nuts made of the same material pass through said openings. On surface of the bottom plate 1 oriented towards the top plate 2, the bottom, conductive non-magnetic strip 7 is provided, with a width of 1 mm, length of 46 mm and thickness of 35 μm, made of gold-plated copper. The bottom, conductive non-magnetic strip 7 is connected at its first end, via the SMP microwave socket, and through the socket opening 12, with the first pole of the microwave signal carrier, in the form of a microwave cable, while at its second end it forms an electrical connection with the first end of the central, surrounding, conductive non-magnetic strip 8, the width of which is equal to the width of the bottom, conductive non-magnetic strip 7 and is equal 1 mm, while its thickness is 100 μm. In the holder according to this embodiment, the central, surrounding, conductive non-magnetic strip 8 is placed on the middle plate 5 from the side of the central opening 6, transversely to the side of the middle plate 5, and its ends overlap both surfaces of the middle plate 5 by 2 mm each. The second end of the surrounding, conductive non-magnetic strip 8 forms an electrical connection with the first end of the top, conductive non-magnetic strip 9, the width of which is also 1 mm and which is placed on the surface of the top plate 2 oriented towards the bottom plate 1. The top, conductive non-magnetic strip 9 passes across the bridge 4. The second end of the top, conductive non-magnetic strip 9 forms an electrical connection with the first end of the central, surface, conductive non-magnetic strip 10 provided on the side of the middle plate 5 opposite to the central, surrounding, conductive non-magnetic strip 8 on the side of the middle plate 5, on the surface oriented towards the top plate 2. The width of the central, surface, conductive non-magnetic strip 10 is 1 mm. The second end of the central, surface, conductive non-magnetic strip 10 is connected with the second pole of the microwave signal carrier via the aforementioned, SMP microwave socket.
[0058] In the holder according to embodiment 1, a sample in the form of a quantum well was placed, 10 nanometre thick, made of cadmium telluride and doped with manganese (Cd.sub.1-xMn.sub.xTe, x=0.26%), the 50 nm thick barriers of which were made of cadmium telluride doped with magnesium (Cd.sub.1-xMg.sub.xTe, x=15%). The well was made using epitaxy, with molecular bundles, on a 350 micrometre thick substrate made of gallium arsenide, covered with a buffer layer of cadmium telluride, 5 micrometre thick. The sample dimensions were 5 mm×5 mm×0.35 mm. Next, radiation with 15 GHz frequency and −15 dBm power was supplied from a generator using a microwave cable. Additionally, through the top openings 3a and 3b in the top plate 2, a laser light beam with a wavelength of 647 nm was directed onto the sample and a measurement of optically detectable magnetic resonance was performed at 1.6 K. The obtained results allowed a conclusion stating that the holder according to the invention ensures the required optical access to the studied sample, while retaining strong coupling with microwave radiation, thus the holder according to the invention enables correct measurements using the ODMR method. Additionally, thanks to its the design, the holder according to the invention was used in measurements using other frequencies in the ranges between 10 GHz and 28 GHz, indicating that it may be re-used without deterioration of functional properties of the system.
EXAMPLE EMBODIMENT 2
[0059] In the second embodiment of the invention, the sample holder for measurements of optically detected magnetic resonance was prepared similarly to the first embodiment, with the difference that one rectangular top opening 3a with dimensions 8 mm×20 mm×0.5 mm is made in the top plate 2. The top opening 3a is placed asymmetrically in relation to the width of the plate, namely, is located closer to one of the longer sides of the top plate 2. The middle plate 5 is provided with a rectangular, central opening 6, which is locate asymmetrically, similar to opening 3a. The central opening 6 has dimensions of 16 mm×20 mm×0.5 mm and is located closer to one of the longer sides of the top plate 2, similar to the top opening 3a. In this embodiment, the top, conductive non-magnetic strip 9, provided on the top plate 2 on the side of the bottom plate 1, is placed in parallel and at the same distance to the two longer sides of the top plate 2. The asymmetrical position of the central opening 6 implies that the surrounding, conductive non-magnetic strip 8 and the central, surface, conductive non-magnetic strip 10 are located closer to one of the two longer sides of the central opening 6. Bridge 4 is absent in this embodiment, wherein the other technical characteristics are analogous to the first embodiment of the invention.
EXAMPLE EMBODIMENT 3
[0060] A sample holder for measurements of optically detected magnetic resonance was prepared in the third embodiment of the invention, similarly to the first embodiment of the invention, with the difference that the central plate 5 comprises of two separated plates 5a and 5b, made of a dielectric material. Plates 5a and 5b are provided with connecting openings 11.
EXAMPLE EMBODIMENT 4
[0061] In the fourth embodiment of the invention, a sample holder for measurements of optically detected magnetic resonance was prepared similarly to the first embodiment, with the difference that the top opening includes eight top openings 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h with a diameter of 1 mm in a series, wherein the top, conductive non-magnetic strip 9, provided on the top plate 2 on the side of the bottom plate 1, is placed in parallel and along the eight top openings 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h, comprising the top opening. Bridge 4 is absent in this sample holder according to the invention in this embodiment, wherein the other technical characteristics are analogous to the first embodiment of the invention.
EXAMPLE EMBODIMENT 5
[0062] In the fifth embodiment of the invention, a sample holder for measurements of optically detected magnetic resonance was prepared similarly to the first embodiment, with the difference that only one, parallel and located at the same distance to the two longer sides of the top plate 2, rectangular top opening 3a with dimensions 0.5 mm×16 mm×0.5 mm is made in the top plate 2. In this embodiment, the top, conductive non-magnetic strip 9 provided on the top plate 2, on the side of the bottom plate 1, surrounds the top opening 3a. In addition, bridge 4 is absent in the sample holder according to this embodiment, wherein the other technical characteristics are analogous to the first embodiment of the invention.
[0063] Maximum magnetic field is obtained in the middle of the sample thanks to this solution, which is of particular importance in the case of small samples.
EXAMPLE EMBODIMENT 6
[0064] In the sixth embodiment of the invention, a sample holder for measurements of optically detected magnetic resonance was prepared, which enables two parallel loops of the electrical circuits to be formed thanks to its design, thus additionally increasing the value of the magnetic component of the microwave on the sample surface. The holder according to this embodiment is similar to the holder according to the fifth embodiment of the invention, with the difference that the bottom, conductive non-magnetic strip 7 is separated into two parallel strip in the area of the central opening 6, i.e. into the bottom, conductive non-magnetic strip 7a and the bottom, conductive non-magnetic strip 7b. In the non-separated part, the bottom, conductive non-magnetic strip 7 is connected, via the SMP microwave socket, through the socket opening (12), with the first pole of the microwave signal carrier, provided in the form of a microwave cable. The central, surrounding, conductive non-magnetic strip 8, provided on the middle plate 5 on the side of the central opening 6, transversely to the side of the middle plate 6, is separated in this embodiment into two parallel strips, i.e. into the central, surrounding, conductive non-magnetic strip 8a and the central, surrounding, conductive non-magnetic strip 8b. In this embodiment, the middle plate 5 has dimensions of 25 mm×55 mm×0.5 mm and is made of FR-4, wherein the central opening 6 has rectangular shape, with dimensions of 16 mm×20×0.5 mm. The bottom, conductive non-magnetic strip 7a forms electrical connection with the first end of the central, surrounding, conductive non-magnetic strip 8a, while the bottom, conductive non-magnetic strip 7b forms electrical connection with the first end of the central, surrounding, conductive non-magnetic strip 8b. In this embodiment, the top, conductive non-magnetic strip 9 is separated into two parallel strips, i.e. the top, conductive non-magnetic strip 9a and the top, conductive non-magnetic strip 9b. The dimensions of the top, conductive non-magnetic strip 9a are 1 mm×25 mm, while the dimensions of the top, conductive non-magnetic strip 9b are 1 mm×25 mm. In parallel, the top opening 3 with dimensions of 1 mm×25 mm×0.5 mm is provided between the top, non-magnetic trip 9a and the top, conductive non-magnetic strip 9b. The second end of the central, surrounding, conductive non-magnetic strip 8a forms electrical connection with the first end of the top, conductive non-magnetic strip 9a, and the second end of the central, surrounding, conductive non-magnetic strip 8b forms electrical connection with the first end of the top, conductive non-magnetic strip 9b. In this embodiment, the central, surface, conductive non-magnetic strip 10 is separated at its first end located at the central opening 6 into two parallel strips, i.e. the central, surface, conductive non-magnetic strip 10a and the central, surface, conductive non-magnetic strip 10b. The second end of the top, conductive non-magnetic strip 9a is connected with the first end of the central, surface, conductive non-magnetic strip 10a, while the second end of the first, conductive non-magnetic strip 9b is connected with the first end of the central, surface, conductive non-magnetic strip 10b. The second end of the central, surface, conductive non-magnetic strip 10a and the second end of the central, surface, conductive non-magnetic strip 10a connect and form the second end of the central, surface, conductive non-magnetic strip 10, which is connected with the second pole of the microwave signal carrier via the SMP microwave socket.
[0065] This solution ensures increased homogeneity of the magnetic component of the microwave, as well as zero gradient of magnetic field along the axis between the conductive, conductive non-magnetic strips.
EXAMPLE EMBODIMENT 7
[0066] In the next, seventh embodiment of the invention, a sample holder for measurements of optically detected magnetic resonance, the design of which ensures formation of two spatially parallel loops of the electrical circuit, connected electrically in series. The holder includes the bottom plate 1, the top plate 2 and the middle plate 5, wherein the bottom plate 1 has dimensions 25 mm×60 mm×1 mm, the top plate 2 has dimensions 25 mm×45 mm×1 mm, while the middle plate has dimensions 25 mm×55 mm×0.5 mm. The middle plate 5 is provided with a rectangular, central opening 6, with dimensions of 16 mm×20 mm×0.5 mm, while the top plate 2 is provided with the top opening 3a with dimensions of 2 mm×16 mm×0.5 mm. The bottom plate 1, the top plate 2 and the middle plate 5 are made of FR-4.
[0067] The central, surface, conductive non-magnetic strip 10 with 1 mm width, 20 mm length and 35 μm thickness is provided on the surface of the middle plate 5 oriented towards the top plate 2. The central, surface, conductive non-magnetic strip 10 is provided asymmetrically in relation to the width of the middle plate 5 and is located 8 mm away from one of the two longer edges of the middle plate 5 and 16 mm away from the other of the two longer edges of the middle plate 5. Two parallel strips, i.e. the top, conductive non-magnetic strip 9a and the top, conductive non-magnetic strip 9b, between which the top opening 3a is provided, are provided on the surface of the top plate 2 oriented towards the bottom plate 1. The central, surrounding, conductive non-magnetic strip 8, provided on the middle plate 5 on the side of the central opening 6, transversely to the side of the middle plate 6, is separated in this embodiment into two parallel strips, i.e. into the central, surrounding, conductive non-magnetic strip 8a and the central, surrounding, conductive non-magnetic strip 8b. In addition, in order to form two circuit loops connected in series, a central, surrounding, conductive non-magnetic strip 8c is provided on the side of the central opening 6 opposite to the central, surrounding, conductive non-magnetic strip 8b, which is C-shaped and turned towards the central opening 6 on the surface of the middle plate 5 oriented towards the top plate 2.
[0068] In this embodiment, the bottom, conductive non-magnetic strip 7 is separated into two parallel strips, i.e. the bottom, conductive non-magnetic strip 7a and the bottom, conductive non-magnetic strip 7b. The bottom, conductive non-magnetic strip 7a is bent at a 90° angle towards the bottom, conductive non-magnetic strip 7b on the side of the SMP connector.
[0069] The middle, surface, conductive non-magnetic strip 10 is connected at its first end with the first pole of the microwave signal carrier, provided as a microwave cable, using the SMP microwave socket. The second end of the central, surface, conductive non-magnetic strip 10 provided at the edge of the central opening 6 is connected with the first end of the top, conductive non-magnetic strip 9a. The second end of the top, conductive non-magnetic strip 9a is connected with the first end of the central, surrounding, conductive non-magnetic strip 8a, while the second end of the central, surrounding, conductive non-magnetic strip 8a is connected with the first end of the bottom, conductive non-magnetic strip 7a. The second end of the bottom, conductive non-magnetic strip 7a is connected with the first end of the central, surrounding, conductive non-magnetic strip 8c. The second end of the central, surrounding, conductive non-magnetic strip 7c is connected with the first end of the top, conductive non-magnetic strip 9b, while the second end of the top, conductive non-magnetic strip 9b is connected with the first end of the central, surrounding, conductive non-magnetic strip 8b, and the second end of the central, surrounding, conductive non-magnetic strip 8b is connected with the first end of the bottom, conductive non-magnetic strip 7b. The second end of the bottom, conductive non-magnetic strip 7 is connected, via the SMP microwave socket, through the socket opening (12), with the second pole of the microwave signal carrier, provided in the form of a microwave cable.
[0070] Such solution enables higher value of the magnetic component of the microwave to be achieved under resonance conditions.
EXAMPLE EMBODIMENT 8
[0071] In the eighth embodiment of the invention, a sample holder for measurements of optically detected magnetic resonance was prepared, similarly to the first embodiment, with the difference that the SMP microwave socket was rotated at an angle of 90° towards its initial orientation in the first embodiment of the invention. The SMP socket is connected, using a solder, at one of its poles with the conductive non-magnetic strip 10 of the middle plate 5, while at the other end is connected with the conductive non-magnetic strip 7 provided on the bottom plate 1. Such a modification of the SMP socket facilitates connection of a microwave cable, as well as placement of the handle according to the invention inside the laser beam.