CN106646738A - Photon and microwave quantum state converter - Google Patents

Abstract

The invention belongs to the technical field of quantum information and discloses a photon and microwave quantum state converter which can help solve a problem that a conventional converter is complex in structure, difficult in manufacturing and assembling operation and low in stability. The photon and microwave quantum state converter comprises a silicon substrate layer and a microwave coplanar waveguide; an optical waveguide, a support rack, a lanthanum aluminate substrate layer and a microlens are arranged on the silicon substrate layer; the microlens is used for converting light output from the optical waveguide to parallel light, the microwave coplanar waveguide is arranged on the lanthanum aluminate substrate layer, a homogeneous rod is mounted on the support rack, and one side of the homogeneous rod is provided with a reflecting face used for reflecting the parallel light which is converted via the microlens; the microlens is mounted on a part, positioned between the optical waveguide and the reflecting face, of the silicon substrate layer; the microlens and the reflecting face of the homogeneous rod form a resonant cavity; the other side, opposite to the reflecting face, of the homogeneous rod is provided with a metal face, and the metal face and a central conductor of the microwave coplanar waveguide form an adjustable capacitor.

Description

A Photon and Microwave Quantum State Converter

technical field

The invention belongs to the technical field of quantum information, in particular to a photon and microwave quantum state converter.

Background technique

In recent years, with the rapid development of quantum information technology, various applications based on quantum effects are emerging. Quantum radar is regarded as the development direction of next-generation radar. Quantum radar uses photons for long-distance detection, and uses the characteristics of photon entanglement to improve its detection, identification and resolution capabilities. However, due to the influence of unfavorable factors such as atmospheric absorption and refraction on the propagation of photons in the atmosphere, the propagation distance of light is greatly shortened, while traditional radars using microwaves as detection methods are less affected. It is desirable to use microwaves as a detection means.

Maxwell proposed that the essence of light is electromagnetic waves. In essence, light has not only wave nature but also particle nature, that is, light has wave-particle duality. A single photon has energy E=hν and momentum p=hν/c (where c is the speed of the photon, ν is the photon frequency, and h represents Planck's constant). Each photon collides with the surface of the object, generating an impulse, that is, the object produces an elastic force on the photon. Objects are also subject to pressure according to Newton's third law.

When light is irradiated on the surface of an object, it is assumed that N photons hit the unit area of the surface of the object per second. If a photon hits the surface of an object vertically and bounces back at a constant speed, that is, the momentum of the photon remains unchanged but its direction changes, the momentum of each photon changes as P=2hν/c, and the radiation pressure on the surface of the object at this time is 2Np (ie 2Nhν/c). According to the light pressure quantum theory, the pressure exerted by light on the surface of an object can be calculated.

The radiation pressure of light acting on the surface of macroscopic or mesoscopic objects is very weak, and people use the light field enhanced by the resonant cavity (or microcavity) to increase the optical pressure effect; that is, the optical force effect is introduced into the cavity. The light causes the optical cavity to vibrate mechanically through the photopressure effect, and the mechanical vibration of the optical cavity can change the capacitance of the LC oscillating circuit, and then modulate the microwave frequency of the microwave oscillating circuit. The conversion between light and microwaves is achieved through a mechanical resonant cavity as an intermediate medium.

At present, there are two commonly used converters between light and microwave:

In the first, the converter consists of 2 electromagnetic resonators, one at an optical frequency and one at a microwave frequency, sharing a mechanical resonator. A mechanical resonator consists of a thin film that vibrates freely. The optical frequency resonator consists of a Fabry-Perot cavity with a membrane that vibrates and modulates the resonant frequency of the optical cavity. The membrane part conducts electricity and forms part of the capacitance in the inductive circuit of the microwave resonator. Because the membrane vibrates freely, it is possible to modulate the capacitance of the microwave circuit, and thus the resonant frequency.

The second type consists of two carefully polished niobium ball mirrors placed in parallel to form a Fabry-Perot cavity. The cavity mirror on the left is fixed and the cavity mirror on the right can move freely. When a beam of classical laser drives the cavity field, the cavity field is excited, and the photons move back and forth in the cavity and hit the movable mirror on the right, which produces radiation pressure on the surface of the mirror and makes the movable mirror deviate from the equilibrium position. Changes in the position of the cavity mirror change the capacitance formed by the right mirror, thereby changing the resonant frequency of the entire microwave circuit.

However, such converters all utilize Fabry-Perot cavity, which has many disadvantages: complex structure, high cost, large volume, difficult assembly and low stability, and Fabry-Perot cavity It is difficult to miniaturize the cavity. These reasons make it difficult to realize commercial applications, and it is difficult to integrate optical resonators and microwave resonators. Therefore, it is an inevitable trend to develop converters that can be integrated and miniaturized.

Contents of the invention

In order to solve the problems of complex structure, difficult preparation, difficult assembly and low stability of existing converters, the present invention provides a photon and microwave quantum state converter, which can realize the integration and miniaturization of waveguides and resonant cavities, It has the characteristics of low manufacturing cost and can realize large-scale.

For solving technical problems, the technical solution adopted in the present invention is:

A photon and microwave quantum state converter, comprising a silicon substrate layer and a microwave coplanar waveguide, the silicon substrate layer is provided with an optical waveguide, a bracket, a lanthanum aluminate substrate layer and used for converting the light output from the optical waveguide A microlens for parallel light, the microwave coplanar waveguide is arranged on the lanthanum aluminate substrate layer; a quality rod is installed on the support, and one side of the quality rod is provided for converting the parallel light converted by the microlens A reflective surface for reflection, the microlens is installed on the silicon substrate layer between the optical waveguide and the reflective surface, the microlens and the reflective surface of the quality rod form a resonant cavity; the other side of the quality rod facing away from the reflective surface is set There is a metal face that forms an adjustable capacitance with the center conductor of the microwave coplanar waveguide.

The size of the microlens is between 400-800 μm.

The microlens is made of single crystal silicon through photolithography and reactive ion beam etching.

The mass of the quality rod is between 10ng-100ng.

The microwave coplanar waveguide also includes coplanar waveguide grounding layers arranged on both sides of the central conductor.

The microwave coplanar waveguide is prepared on the lanthanum aluminate substrate layer by using yttrium barium copper oxide (YBCO).

The optical waveguide is an SOI ridge optical waveguide.

Compared with the prior art, the present invention has the following beneficial effects:

The photon and microwave quantum state converter provided by the present invention includes a silicon substrate layer and a microwave coplanar waveguide, and the silicon substrate layer is provided with an optical waveguide, a bracket, a lanthanum aluminate substrate layer and a Light is converted into a microlens of parallel light, the microwave coplanar waveguide is arranged on the lanthanum aluminate substrate layer; a quality rod is installed on the support, and one side of the quality rod is provided with a A reflective surface for reflecting parallel light, the microlens is installed on the silicon substrate layer between the optical waveguide and the reflective surface, and the microlens and the reflective surface of the quality rod form a resonant cavity; the other part of the quality rod facing away from the reflective surface A metal surface is arranged on the side, and the metal surface forms an adjustable capacitance with the center conductor of the microwave coplanar waveguide. The working principle of the present invention is: use the microlens to converge the light output by the optical waveguide, make the microlens and the mass rod form a resonant cavity, use the light pressure effect generated by the back and forth reflection of light in the resonant cavity, make the mass rod vibrate, and then change the mass The capacitance composed of the rod and the microwave coplanar waveguide can modulate the microwave frequency and realize the conversion between photon and microwave quantum states. In a new resonant cavity proposed by the present invention, the size and quality of the microlens and the quality rod are in the order of μm and ng respectively, thereby realizing the miniaturization of the resonant cavity; It is made with reactive ion beam etching technology, the optical waveguide is made on the silicon substrate layer, the microwave coplanar waveguide is made on the lanthanum aluminate substrate layer using superconducting yttrium barium copper oxide (YBCO), and the mass rod is placed on the silicon substrate layer through the bracket. On the substrate layer, the present invention has the characteristics of high degree of integration; the preparation technology of optical waveguide and microwave coplanar waveguide is relatively mature, and the manufacturing cost of microlens and quality rod is relatively low; therefore, compared with the prior art, the present invention has structural The characteristics of simplicity, miniaturization, high degree of integration and low manufacturing cost facilitate the realization of large-scale production.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the cooperation schematic diagram of microlens of the present invention, mass rod and microwave coplanar waveguide;

Marks in the figure: 1. Silicon substrate layer, 2. Optical waveguide, 3. Microlens, 4. Reflective surface, 5. Metal surface, 6. Mass rod, 7. Bracket, 8. Center conductor, 9. Coplanar waveguide grounding Layer, 10, microwave coplanar waveguide, 11, lanthanum aluminate substrate layer.

detailed description

The present invention will be further described below in conjunction with the embodiments, and the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other used embodiments obtained by persons of ordinary skill in the art without creative efforts all belong to the protection scope of the present invention.

In conjunction with the accompanying drawings, the photon and microwave quantum state converter provided by the present invention includes a silicon substrate layer 1 and a microwave coplanar waveguide 10, and the silicon substrate layer 1 is provided with an optical waveguide 2, a bracket 7, and a lanthanum aluminate substrate layer 11 and a microlens 3 for converting the light derived from the optical waveguide 2 into parallel light, the microwave coplanar waveguide 10 is arranged on the lanthanum aluminate substrate layer 11, the bracket 7 is equipped with a quality rod 6, and the One side of the mass rod 6 is provided with a reflective surface 4 for reflecting the parallel light converted by the microlens 3, and the microlens 3 is installed on the silicon substrate layer 1 between the optical waveguide 2 and the reflective surface 4. The lens 3 and the reflective surface 4 of the rod 6 form a resonant cavity, and the other side of the rod 6 facing away from the reflective surface 4 is provided with a metal surface 5, and the metal surface 5 forms a center conductor 8 with the microwave coplanar waveguide 10. Adjustable capacitance.

The working principle of the present invention is: use the microlens to converge the light output by the optical waveguide, make the microlens and the mass rod form a resonant cavity, use the light pressure effect generated by the back and forth reflection of light in the resonant cavity, make the mass rod vibrate, change the mass rod The capacitance composed of the coplanar waveguide with the microwave, the change of the capacitance is the change of the frequency of the LC oscillating circuit, thereby modulating the frequency of the microwave, and finally the whole system realizes the conversion between light and microwave through the intermediary of the resonant cavity.

The microlens 3 of the present invention is made of single crystal silicon through silicon photolithography or reactive ion beam etching. The size of the microlens 3 is on the order of μm, between 400-800 μm. As a preferred mode of the present invention, the aperture of the microlens 3 is 500 μm.

The quality of the mass rod 6 of the present invention is in the order of ng, and the quality is between 10ng-100ng

The microwave coplanar waveguide 10 of the present invention further includes coplanar waveguide grounding layers 9 arranged on both sides of the central conductor 8 .

As a preferred mode of the present invention, the optical waveguide 2 is an SOI ridge optical waveguide.

In a new resonant cavity proposed by the present invention, the size and quality of the microlens and the quality rod are in the order of μm and ng respectively, thereby realizing the miniaturization of the resonant cavity; Or reactive ion beam etching technology, the optical waveguide is made on the silicon substrate layer, the microwave coplanar waveguide is prepared on the lanthanum aluminate substrate layer using yttrium barium copper oxide (YBCO), and the light rod is placed on the silicon substrate through the bracket On the bottom layer, the present invention has the characteristics of high integration; the preparation technology of optical waveguide and microwave coplanar waveguide is relatively mature, and the manufacturing cost of microlens and quality rod is relatively low; therefore, compared with the prior art, the present invention has simple structure , miniaturization, high degree of integration, and low manufacturing cost, it is easy to realize large-scale production.

Embodiment one

The photon-to-microwave quantum state converter of this embodiment includes a silicon substrate layer and a microwave coplanar waveguide, on which an optical waveguide, a bracket, a lanthanum aluminate substrate layer, and a Light is converted into a microlens of parallel light, the microwave coplanar waveguide is arranged on the lanthanum aluminate substrate layer; a quality rod is installed on the support, and one side of the quality rod is provided with a A reflective surface for reflecting parallel light, the microlens is installed on the silicon substrate layer between the optical waveguide and the reflective surface, and the microlens and the reflective surface of the quality rod form a resonant cavity; the other part of the quality rod facing away from the reflective surface A metal surface is arranged on the side, and the metal surface forms an adjustable capacitance with the center conductor of the microwave coplanar waveguide.

Embodiment two

The photon-to-microwave quantum state converter of this embodiment includes a silicon substrate layer and a microwave coplanar waveguide, on which an optical waveguide, a bracket, a lanthanum aluminate substrate layer, and a Light is converted into a microlens of parallel light, the microwave coplanar waveguide is arranged on the lanthanum aluminate substrate layer; a quality rod is installed on the support, and one side of the quality rod is provided with a A reflective surface for reflecting parallel light, the microlens is installed on the silicon substrate layer between the optical waveguide and the reflective surface, and the microlens and the reflective surface of the quality rod form a resonant cavity; the other part of the quality rod facing away from the reflective surface A metal surface is arranged on the side, and the metal surface forms an adjustable capacitance with the central conductor of the microwave coplanar waveguide; the size of the microlens is between 400-800 μm.

Embodiment three

The photon-to-microwave quantum state converter of this embodiment includes a silicon substrate layer and a microwave coplanar waveguide, on which an optical waveguide, a bracket, a lanthanum aluminate substrate layer, and a Light is converted into a microlens of parallel light, the microwave coplanar waveguide is arranged on the lanthanum aluminate substrate layer; a quality rod is installed on the support, and one side of the quality rod is provided with a A reflective surface for reflecting parallel light, the microlens is installed on the silicon substrate layer between the optical waveguide and the reflective surface, and the microlens and the reflective surface of the quality rod form a resonant cavity; the other part of the quality rod facing away from the reflective surface The side is provided with a metal surface, and the metal surface forms an adjustable capacitor with the central conductor of the microwave coplanar waveguide; the size of the microlens is between 400-800 μm; the microlens is made of single crystal silicon through photoetching or reaction Manufactured by ion beam etching.

Embodiment Four

On the basis of any of the above-mentioned embodiments, the mass of the mass rod is between 10ng-100ng.

Embodiment five

On the basis of any of the above embodiments, the microwave coplanar waveguide further includes coplanar waveguide grounding layers arranged on both sides of the central conductor.

Embodiment six

On the basis of any of the above embodiments, the microwave coplanar waveguide is prepared on the lanthanum aluminate substrate layer by using yttrium barium copper oxide YBCO.

Embodiment seven

On the basis of any of the above embodiments, the optical waveguide is an SOI ridge optical waveguide.

Claims (7)

1. A kind of photon and microwave quantum state converter, it is characterized in that, comprise silicon substrate layer and microwave coplanar waveguide, described silicon substrate layer is provided with optical waveguide, support, lanthanum aluminate substrate layer and is used for will from light The light output in the waveguide is converted into a microlens of parallel light, the microwave coplanar waveguide is arranged on the lanthanum aluminate substrate layer; a quality rod is installed on the support, and one side of the quality rod is provided for The reflective surface on which the parallel light converted by the lens is reflected. The microlens is installed on the silicon substrate layer between the optical waveguide and the reflective surface. The microlens and the reflective surface of the mass rod form a resonant cavity; the mass opposite to the reflective surface The other side of the rod is provided with a metal surface, which forms an adjustable capacitance with the central conductor of the microwave coplanar waveguide. 2. The photon-to-microwave quantum state converter according to claim 1, characterized in that the size of the microlens is between 400-800 μm. 3 . The photon and microwave quantum state converter according to claim 2 , wherein the microlens is made of single crystal silicon through photolithography and reactive ion beam etching. 4 . 4. The photon-to-microwave quantum state converter according to claim 1, wherein the mass of the mass rod is between 10ng-100ng. 5 . The photon-to-microwave quantum state converter according to claim 1 , wherein the microwave coplanar waveguide further comprises coplanar waveguide grounding layers disposed on both sides of the central conductor. 6 . The photon and microwave quantum state converter according to claim 1 , wherein the microwave coplanar waveguide is prepared on a lanthanum aluminate substrate layer using yttrium barium copper oxide. 7. The photon-to-microwave quantum state converter according to any one of claims 1-6, wherein the optical waveguide is an SOI ridge optical waveguide.