CN-119376096-B - Optical resonance peak Q value regulation and control method and application

CN119376096BCN 119376096 BCN119376096 BCN 119376096BCN-119376096-B

Abstract

The method comprises the steps of 1) obtaining inherent attribute parameters and/or environment refractive index change values delta n of a target system, wherein the target system is a multi-resonance coupling system and/or an asymmetric BIC system, 2) constructing an arithmetic expression based on the environment refractive index change values delta n and/or the obtained inherent attribute parameters in the step 1), and constructing a relation expression between a resonance peak Qr value and the environment refractive index change values delta n when the target system is the multi-resonance coupling system. And 3) calculating based on the formulas 1 and 2, and adjusting the environment refractive index change value delta n or changing the asymmetry factor alpha through the calculation result of the Qr value and the adjustment purpose so as to realize the adjustment and control of the Qr value. The invention can realize the control of the Qr value through the change of the environment refractive index.

Inventors

WEN LIAOYONG
SUN JIACHENG
WANG XUDONG
YAN SISI

Assignees

西湖大学

Dates

Publication Date: 20260505
Application Date: 20241031

Claims (6)

1. A method for regulating and controlling Q value of an optical resonance peak is characterized in that, The method comprises the following steps: 1) Acquiring inherent attribute parameters of a target system and an environment refractive index change value delta n; the target system is a multi-resonance coupling system and/or an asymmetric BIC system; the multi-resonance coupling system is provided with a harmonic oscillator 1 and a harmonic oscillator 2, wherein the natural frequency of the harmonic oscillator 1 is red shifted along with the increase of delta n, the natural frequency of the harmonic oscillator 2 is not changed along with delta n, the frequency of the harmonic oscillator 1 in a zero decoupling state is equal to the frequency of the harmonic oscillator 2, the natural loss of the harmonic oscillator 1 is not changed along with delta n, and the natural loss of the harmonic oscillator 2 is increased along with the increase of delta n; the asymmetric BIC system comprises two nanoparticle super-surfaces with different diameters or heights or materials or spatial displacement; 2) Constructing an associated Qr value based on the ambient refractive index variation value Δn and the obtained intrinsic property parameters of step 1); When the target system is a multi-resonance coupling system, the acquired inherent attribute parameters comprise an upper energy branch frequency omega of the coupling system, an initial attenuation coefficient gamma 2 ' of the harmonic oscillator 2 in a zero decoupling state, coupling strength g between the harmonic oscillator 1 and the harmonic oscillator 2, a pull ratio split omega R , sensitivity S 1 of the eigenfrequency of the harmonic oscillator 1 to an environment refractive index change value delta n, sensitivity S 2 of the eigenfrequency of the harmonic oscillator 2 to the environment refractive index change value delta n, inherent frequency omega 1 of the harmonic oscillator 1, inherent frequency omega 2 of the harmonic oscillator 2 and a non-radiation attenuation coefficient gamma n ; the relation between the resonance peak Qr value and the ambient refractive index variation deltan is constructed as shown in the following formula 1: Formula 1: ; Q r is a radiation quality factor, namely a resonance peak Q r value, ω is an upper energy branch frequency of a strong coupling system, γ 2 ' is an initial attenuation coefficient of a harmonic oscillator 2 in a zero decoupling state, g is a coupling strength between the harmonic oscillator 1 and the harmonic oscillator 2, Ω R is a Lax split, Δn is an environment refractive index change value, S 1 is sensitivity of an eigen frequency of the harmonic oscillator 1 to the environment refractive index change value Δn, S 2 is sensitivity of the eigen frequency of the harmonic oscillator 2 to the environment refractive index change value Δn, i is a pure imaginary number and defined as i 2 =-1,ω 1 is a natural frequency of the harmonic oscillator 1, ω 2 is a natural frequency of the harmonic oscillator 2, and γ n is a non-radiation attenuation coefficient; When the target system is an asymmetric BIC system, the acquired inherent attribute parameters comprise an asymmetry factor alpha; the radiation quality factor according to the following asymmetric BIC system is regularly formula 2: formula 2: ; wherein Q r is a radiation quality factor, namely a resonance peak Qr value, alpha is an asymmetry factor, and a and b are obtained by substituting at least two points of characterization data Q r and alpha into a calculation fitting result; 3) Formulas 1 and 2 based on the above step 2): When the target system is a multi-resonance coupling system, substituting the intrinsic attribute parameter to calculate according to a formula 1, and adjusting the environment refractive index change value delta n according to a calculation result and an adjusting purpose of the Qr value so as to realize the adjustment and control of the Qr value; The method for adjusting the environment refractive index change value delta n comprises adjusting and/or replacing a liquid system or an atmosphere environment where a target multi-resonance coupling system is located; When the target system is an asymmetric BIC system, selectively modifying the nanoparticles of the asymmetric BIC system according to the regulation purpose, and changing an asymmetric factor alpha to realize regulation and control of the Qr value; When the target system has the characteristics of a multi-resonance coupling system and an asymmetric BIC system, changing an environment refractive index change value delta n and/or an asymmetric factor alpha in at least one mode to realize the regulation and control of the Qr value; When the target system is an asymmetric BIC system or contains the characteristics of the asymmetric BIC system, the Qr value is regulated and controlled through the formula 2 after the regulation and control requirement is determined according to the absorbance expression of the resonance peak of the formula 6; formula 6: ; Abs is absorbance, x is the maximum absorption value of the system and is calculated by substituting 1, Q r is a radiation quality factor, Q n is a non-radiation quality factor, ω is the frequency of any harmonic oscillator in a zero decoupling state, and ω r is the natural oscillation frequency of the system when no loss exists; Where the target system comprises asymmetric nanostructured NPs-a and nanostructured NPs-b; The nano-structures NP-a and NP-b have different structure widths and/or structure radii and/or structure heights and/or spatial relative positions, wherein the structure widths and/or structure radii and/or structure heights of the nano-structures NP-a are greater than the structure widths and/or structure radii and/or structure heights of the nano-structures NP-b; The selective modification treatment is to modify the surface of the nano-structure NP-a and/or nano-structure NP-b to form local refractive index change.
2. The method for adjusting and controlling the Q value of an optical resonance peak according to claim 1, wherein, Step 2), constructing a relation between a resonance peak Qr value and an environment refractive index change value delta n, combining a critical coupling mechanism, and combining a formula 1 with a formula 3, namely a formula 1 for correcting the coupling strength between the harmonic oscillator 2 and a formula 4 for calculating a conversion coefficient; Formula 3: ; In the formula 3, g n is the result of correcting the coupling strength g between the harmonic oscillator 1 and the harmonic oscillator 2 by the environment refractive index change value delta n, delta n is the environment refractive index change value, S 1 is the sensitivity of the eigenfrequency of the harmonic oscillator 1 to the environment refractive index change value delta n, and S 2 is the sensitivity of the eigenfrequency of the harmonic oscillator 2 to the environment refractive index change value delta n; formula 4: ; Wherein m is a conversion coefficient of a difference between intrinsic attenuation coefficient changes passively generated due to introduction of a difference between eigenfrequency changes generated by harmonic oscillator 1 and harmonic oscillator 2 in a sensing process, deltan is an ambient refractive index change value, S 1 is sensitivity of eigenfrequency of harmonic oscillator 1 to the ambient refractive index change value Deltan, and S 2 is sensitivity of eigenfrequency of harmonic oscillator 2 to the ambient refractive index change value Deltan.
3. The method for adjusting and controlling the Q value of an optical resonance peak according to claim 1, wherein, The formula 1 is modified by combining the formula 3 and the formula 4 to obtain the following formula 5: formula 5: ; Wherein Q r is a radiation quality factor, namely a resonance peak Qr value, ω is an upper energy branch frequency of a strong coupling system, γ 2 ' is an initial attenuation coefficient of the harmonic oscillator 2 in a zero decoupling state, m is a conversion coefficient of a difference between attenuation coefficient changes of intrinsic factors passively generated due to introduction of a difference between eigenfrequency changes of the harmonic oscillator 2 and the harmonic oscillator 1 in a sensing process, g n is a result of correcting a coupling strength g between the harmonic oscillator 2 and the harmonic oscillator 1 by an environmental refractive index change value Δn, Ω R is a split ratio, Δn is an environmental refractive index change value, S 1 is a sensitivity of the eigenfrequency of the harmonic oscillator 1 to the environmental refractive index change value Δn, S 2 is a sensitivity of the eigenfrequency of the harmonic oscillator 2 to the environmental refractive index change value Δn, i is a pure virtual number and defined as i 2 =-1,ω 1 is an eigenfrequency of the harmonic oscillator 1, 2 is an eigenfrequency of the harmonic oscillator 2, and γ n is a non-radiation attenuation coefficient.
4. The method for adjusting and controlling the Q value of an optical resonance peak according to claim 1, wherein, The local refractive index change formed by the surface modification of the nano-structure NP-a is inversely related to the radiation quality factor Q r ; the local refractive index change formed by the surface modification of the nano-structure NP-b is positively correlated with the radiation quality factor Q r .
5. A method according to claim 1 to 4, wherein, The method is used for modulating and/or designing and/or modifying an optical sensing system and/or an optical sensing device.
6. A use according to claim 5, characterized in that, The optical sensing system and/or optical sensing device comprises a biosensing system and/or biosensing device.

Description

Optical resonance peak Q value regulation and control method and application Technical Field The invention belongs to the field of optical physics, and particularly relates to a method for regulating and controlling an optical resonance peak Q value and application thereof. Background Optical physics is the science of studying the interaction of light with matter. Light is an electromagnetic wave, and its phenomena such as propagation, reflection, refraction, diffraction, and scattering are all affected by the nature of the substance. These basic physical processes form the basis for the operation of the optical sensing device and the system. The fluctuating properties of light, particularly its frequency and wavelength, can be used to accurately measure the optical properties of a substance, including refractive index, absorption coefficient, and scattering properties. And optical sensors make use of the physical properties of light to detect and quantify changes in external factors. They are widely used in environmental monitoring, chemical analysis, materials science and biomedical engineering. The optical sensor has higher sensitivity, faster response time and better tamper resistance than conventional electrochemical sensors. With the development of micro-nano processing technology, the size of the optical sensor is continuously reduced, the integration level is continuously improved, and the optical sensor provides possibility for realizing portable and low-cost sensing equipment. While biosensing technology is an extension of the application of optical sensors in the field of biology. The identification and detection of biomolecules is critical to the fields of disease diagnosis, environmental monitoring, food safety and the like. However, conventional biological detection methods often rely on complex labeling procedures and large analytical equipment, which limit their range of applications and convenience. For example, the conventional plasmon SPR configuration is the most commonly used commercial biosensing platform, but the complex oblique incidence prism coupling and detection optical path system leads to large-size and expensive equipment, and large-scale application and integration are difficult. Therefore, a novel biosensing technology is developed, label-free, high-sensitivity, quick-response and portable detection can be realized, and urgent demands of scientific research and industry are met. In the present, the visible/near infrared optical super-surface biosensor is a universal label-free biosensor, which is widely applied in scientific research and daily life. Although the marking-free device can be realized, the device still needs to be combined with a super-continuous light source, a large-scale spectrometer and other equipment to complete the optical sensing test, so that a test system is complex and huge, and portability and universality are not realized. In addition, in order to improve the sensing performance, the main current research direction is to make the resonance peak Q value (that is, qr value) higher (line width narrowing) by complex design and precise processing. The problems of rising preparation cost, increasing testing difficulty and the like are further caused, more precise and expensive testing equipment is needed, and the aim of practicality and integration of the optical biosensing system is overcome. In recent years, the optical biosensing system is further integrated by combining the proposal of the optical supersurface with high Q value and the concept of spectrum imaging type biosensing without light. However, in the sensing process, the matching problem of a dynamic high-Q value narrow linewidth resonance peak and a static specific wavelength light source is always outstanding. The problems mainly include three sources, namely, the contradiction that the frequency of an illumination light source is fixed, but the resonant frequency moves along with a measured object, frequency mismatch is easy to cause, so that response is irregular, and the robustness of the high-Q-value optical super-surface to preparation defects is low, and further, the resonant frequency is offset to cause mismatch. 3. The problem of mismatch between the frequency and the bandwidth not only reduces the reliability of imaging signals, but also causes the chip preparation to highly depend on high-precision processing equipment, thus greatly restricting the practicability and the universality of the integrated imaging optical sensor. Aiming at the problems, the prior art has fewer solutions, the only effective method at present is to design and prepare a series of two-dimensional BIC super-surface array structures with different asymmetric symmetrical coefficients by utilizing the constraint state (BIC, bound state in continuum) in the continuous domain to carry out pixelated scanning (a Q-scanning scheme for short) from low to high on the Q value, so that the condition that the resona