Micro-nano structure with unique optical properties are commonly used in micro-nano optics to achieve luminescence enhancement of fluorescent substance. In order to improve the luminous efficiency of quantum dots (QDs), a dimer structure composed of two silicon nanospheres of different sizes is proposed. By utilising the finite-difference time-domain (FDTD) method, the enhancement in the quantum yield and fluorescence excitation rate are investigated to illustrate the fluorescence enhancement effect of the silicon nanospheres dimer. Results show that the luminous intensity of CdSe QDs can be greatly enhanced by dimers composed of two silicon nanospheres of different sizes. When the two silicon nanospheres have smaller diameter and smaller gap, the quantum yield and fluorescence excitation rate of the QDs can be enhanced more. In particular, when the diameter of the two silicon nanospheres is 100 nm and the gap is 10 nm, the fluorescence intensity of the CdSe quantum dot can be enhanced by about 209 times. The results are of certain guiding significance for the design and development of high-performance quantum dot photoluminescence devices.

In order to meet the requirement for detecting the methane (CH4) leakage in the daily maintenance of the network of gas pipelines in cities, an inhaled portable CH4 detector based on tunable diode laser absorption spectroscopy (TDLAS) technique has been developed, whose weight is only 1.4 kg and volume is 22 cm×10 cm×10 cm. A distributed feedback laser with a central wavelength of 1654 nm is used as the light source in the instrument and an optical multi-pass cell with a physical basic length of 8.5 cm and an effective optical path of 2.25 m is integrated. The system based on STM32F405 generates a stable modulation laser by controlling laser, and acquires the absorption signal by the signal acquisition and process unit, then a digital lock-in amplifier is used to extract the second harmonic component in the signal to get the concentration of gas. Calibration and stability tests of the detector are carried out. Results show that there is a good linear relationship between the amplitudes of second harmonic signal and gas concentrations. The measurement accuracy of system is ±3.05% and the minimum detectable limit is 0.88 ppm. The precision and portability of the instrument meet the requirements of actual measurement.

At room temperature, the earth’s infrared energy is huge, but it can not be effectively used because of its wide band, low strength and easy to conduct. The earth’s infrared radiation (8～15μm) of the wide bandwidth at room temperature is converted into the water medium at relatively narrow bandwidth (9.56～10.02μm) and stable temperature, the water medium radiate the infrared long-wave outward through the capillary network, and then realize the energy conversion through the long-wave antenna. Results show that the radiation energy and energy density of the capillary network per unit area flowing through the media medium is huge. The parameters of long-wave receiving antenna and antenna array are calculated. Considering the 16 °C water medium, the conversion rate of infrared radiation can reach 94%.

Metasurface structures based on subwavelength nanoscale units (meta-atoms) have been innovated and greatly enriched the technique of light field regulation. Therefore, it is of great value to study and design metasurface structures with unique properties and functions in light field regulation. The induced electric, magnetic, electro-magnetic and magneto-electric responses within the symmetrical and asymmetrical metal- dielectric- metal (MDM) triangular prism meta-atoms are calculated by using the polarizability tensors of the meta-atoms. The polarization-independent MDM triangular prism periodic structure is designed. The transmission and reflectance spectrum of the MDM meta-surfaces are studied by finite difference time domain (FDTD) simulation and theoretical calculation method. The two results are well consistent with each other. It is found that the reflection spectrum of the symmetric metasurface is identical whether the light incident is from upward or downward. However, the reflection spectrum of the asymmetric metasurface depends on the direction of the incident light when the incident light frequency is around the resonant mode. The results reported here are helpful for the realization of asymmetrical metasurface with arbitrary reflectivity.

In order to simplify the system structure, a variable long-distance transmitter-receiver shared refractive optical system is designed by combining the laser transmitting system with the imaging receiving optical system. The system uses a spectroscope to separate 1064 nm laser and visible light. By adjusting the focal plane of the imaging system and the front lens position of the transmitting system, it can transmit laser to objects in the range of 300～2000 m and receive image. Combining the two functions, the miniaturization and lightweight of laser optical system are realized by means of transmitting and receiving through a common optical path. According to the PW method, the initial structure of the front and rear lenses of the main optical path is designed and optimized using Zemax software, which greatly improves the imaging quality of the receiving system and energy concentration of the emitting laser. The final design result meets the design requirements. In the object distance range from 300 m to 2000 m, the emitted spot size of the system is reasonable and it can be clearly imaged.

The interaction between fundamental mode Gaussian optical field (HG00), high-order Hermite-Gaussian optical field (HG10) and subwavelength single-metal slits is investigated by numerical simulation. It is found that under the same misalignment coupling, the HG10 light field can induce obvious unidirectional excitation of surface plasmon polariton (SPP). On this basis, a subwavelength metal slit pair structure is proposed. Numerical simulation shows that under appropriate misalignment coupling, the HG10 mode field and the subwavelength metal slit pair can induce more remarkable unidirectional excitation of SPP. By optimizing the slit pitch and incident light wavelength, the maximum split ratio reaches 2.6. The finite-difference time-domain method is used for numerical simulation in design optimization. The metal slit structure is simple and easy to prepare, and the asymmetrical excitation of SPP has the characteristics of dynamic adjustment, which has potential application value in micronanophotonic integration and nanometer measurement.

Time-dependent driven harmonic oscillator system is closely related to many practical physical problems. SU(1,1) Lie algebra is used to solve the problem of SU(1,1)h(3) time-dependent forced harmonic oscillator system. Firstly, the time evolution operator of Hamilton H^0(t) is solved, then the time evolution operator of V^(t) in interaction representation is solved. Finally, the general time evolution operator of system is obtained. One example is given to demonstrate the correctness of the method.

The lasers with wavelengths of 633 nm and 1319 nm are taken as examples to investigate the laser coupled confocal system. In order to satisfy the design requirement that the convergence angle of two wavelength laser beams is less than 10° after focusing, two solutions are proposed. One is to use a reflector and a dichroic mirror to achieve a common optical path for the double wavelength lasers, and then to achieve confocal via off-axis parabolic reflection. The other is to use a combination lens to couple the dual-wavelength laser into a two-in-one combiner, which uses a single-mode fiber with a core of 9 μm and a numerical aperture (NA) of 0.14. A coupling lens group based on fiber and laser parameters is designed. Considering the second method, the experimental method and measurement results are given, and the coupling efficiencies of the two wavelength lasers are calculated. The experimental results show that the combined lens coupling method can achieve two-wavelength lasers combining with high coupling efficiency. The coupling efficiencies of the system are greater than 40%, 30% respectively when the input wavelength are 633 nm, 1319 nm. The experimental results meet the design requirements and achieve the desired results.

The dynamical properties of cavity optomechanical system are investigated for an initial state composed of squeezed vacuum state and number state. The effect of system parameters on the linear entropy and Wigner function is analyzed. The numerical results indicate that the Wigner function for mechanical mode can be effectively manipulated by adjusting the value of squeezing factor r. Especially, increasing the value of r can enhance significantly the entanglement between cavity mode and mechanical mode. Both negativity depth and region of the Wigner function for optical mode decrease with increasing the value of the mechanical mode parameter k.

The optically mediated oscillation transfer between the coupled cantilevers in the optomechanical system based on two-coupled-cantilever is realized. A tunable two-mode optomechanical system is constructed by tuning the intrinsic frequency of one of the cantilevers by optical trapping. A parametric driving field is applied through periodically modulating the trapping power in order to parametrically couple the two cantilevers, which enables further experimental demonstration of coherent oscillation transfer between the cantilevers. The method is helpful to construct coherent phonon devices based on coupled micromechanical oscillator arrays.

For diverse three-node vertical-cavity surface-emitting laser (VCSEL) networks, a new criterion of the globally complete chaos synchronization (GCCS) among all node lasers is proposed by using the master-stability function (MSF). It is found that GCCS can be achieved for an arbitrarily given three-node VCSEL networks when two points determined by constant row sum and two transversal eigenvalues fall into the region of stability where maximum Lyapunov exponent (MLE) is negative and the MLE as a function of constant row sum and the eigenvalue associated to perturbations within the synchronization manifold is positive. The criterion can be generalized to multiple (more than four) nodes VCSEL networks. Based on the theoretical criterion and synchronization error theory, the synchronization properties in three-node VCSEL network with the ring topology are further explored. As a result, the theoretical criterion is in excellent agreement with the numerical results, which indicate that the theoretical criterion is valid and feasible.

In order to solve the complex problem of concatenated GHZ(C-GHZ) state preparation, an improved scheme of C-GHZ state based on weak cross Kerr nonlinearity is proposed. Combining with the homodyne detection technology and the classical feedforward, the packaged optical element module and HWP22.5°half-wave plate are used to deduce the nm C-GHZ state from the simple C-GHZ state after repeated operation. Finally the preparation law of C-GHZ state is obtained. The required number of auxiliary single photons is nm, the number of modules is nm－1, and the number of HWP22.5° is n. The success rate simulation and feasibility analysis are conducted. Results show that increasing the amplitude intensity of coherent state |α〉 and reducing the loss of photon transmission can improve the success rate of C-GHZ state preparation.

Optical quantum entanglement system is one of the most important systems for quantum information processing. The inevitable coupling between the entangled system and quantum noise will lead to the failure of the quantum information processing. Therefore, it is very important to investigate the effect of quantum noise on the entangled system and obtain the corresponding experimental laws. The properties and physical operator representation of optical typical quantum noise are given theoretically. In the experiment, various typical optical quantum noises are successfully simulated by using different optical devices or combination of devices. Taking the quantum bit flip noise as an example, the effect of noise on two qubit entanglement system is studied. Results show that for two qubit entangled systems, when the entanglement degree of the entanglement source is the same, the bit-flip noise is more likely to destroy the entanglement coherence than the phase-shift noise, and the ability of bit-phase-flip noise to destroy the entanglement property is between the former two.

A physical model for a two-level atom simultaneously coupled to multiple Bosonic reservoirs is investigated. The explicit expression of quantum speed limit is obtained. Analysis shows that as long as the number of reservoirs satisfies certain conditions, whether it is strong coupling or weak coupling, the system will show a non-Markov effect. Numerical simulation shows that the non-Markovian effect of the system increases with the increasing of reservoir number. Further investigation shows that the stronger the non-Markov effect is, the faster the evolution acceleration of quantum system will be.

In order to realize long-term automatic observation of surface reflectivity and improve the frequency of site calibration, a method of surface reflectivity measurement based on ratiometric radiation measurement is proposed. Synchronous observation is carried out by using spectally-reflective automatic spectroradiometer and hyperspectral irradiance meter. Surface radiance and total atmospheric illuminance at the same time are obtained, and the surface reflectance parameters can be obtained by the ratio method. The laboratory radiation calibration based on standard radiation source is designed to obtain the calibration coefficients of the radiometer and illuminometer respectively, and then the input system parameters based on the ratio method to measure the surface reflectivity are obtained. The standard board measurement comparison experiment is carried out outdoors. The relative deviation between the visible-near-infrared ratio radiation measurement and the reference plate reflectance value after laboratory calibration is within 3%, and the effectiveness of the measurement system is verified.

In view of the intuitive characteristics of atmospheric visibility and the urgent need of infrared photoelectric technology, a calculation and measurement method of atmospheric infrared visibility is proposed, and an atmospheric infrared visibility measuring instrument is developed. The instrument uses 1064 nm wavelength laser as the light source and Xenics camera as detector to measure infrared visibility. A traditional background subtraction method and the shift-phase subtraction are used to carry out the contrast experiment when dark background processing is carried out. The measurement results are also processed by the slope and Klett integration method in the process of visibility inversion. Results show that the infraredvisibility measured by the system is basically the same as that of the Belfort visibility meter, and the correlation coefficient is more than 80%, which shows that the calculation and measurement results of infrared visibility are reliable.

In recent years, the ground-based observation experiments of lunar irradiance have been increasing. In order to meet the high-precision and high-frequency observation of the lunar radiation on the ground, it is necessary to develop a high-precision lunar automatic tracking system for tracking experiments. The designed tracking system uses the lunar position algorithm to obtain the zenith angle and azimuth of the moon for apparent motion tracking, and then uses the photoelectric tracking with the four-quadrant detector as the core device to accurately track the moon. The external field tracking experiments have shown that the combination of apparent motion tracking and photoelectric tracking has high-precision tracking effect. The tracking accuracy is within ±0.2°, indicating that the tracking system has high accuracy and reliability.

A two-dimensional servo turntable based on DC brushless torque motor is developed, which has the function of solar tracking and all-sky scanning. It can achieve 10′′ positioning accuracy on two freedom degrees of 360° horizontal and 180° pitching, which can meet the requirement of tracking precision of fully automatic satellite tracking observation. The turntable uses torque motors and other corresponding low-temperature devices suitable for low-temperature environments, and can work normally in the range from －40～50 °C to meet the demand of field application. The compact and lightweight design makes the turntable more portable. The control system of the turntable adopts a wide temperature development board based on ARM9 architecture, and the Linux kernel is transplanted into the board. The kernel supports the addition of a variety of functional modules. It is beneficial to the improvement and perfection of the function in the later stage of the turntable. The turntable can not only operate under the control of the upper computer software, but also work independently under the guidance of its own internal program. It is equipped with micro-fiber spectrometer detection module, which can be used for spectral scanning measurement of skylight background radiation.

Due to the deficiency of classic electromagnetic theory in characterizing the scattering intensity, a quantum mechanical model based on spontaneous Raman scattering is proposed and deduced, where matter and electromagnetic waves are dealt with separately, and the interaction between them are considered as perturbations. The theories of optical fiber quantum sensing are studied through the analysis of scattering in fiber core. On this basis, the principle of distributed quantum sensor based on Raman scattering is studied. And a model of fiber quantum temperature sensing based on Raman scattering is then proposed. A distributed fiber quantum sensing experimental system is developed. The technical parameters of the distributed quantum temperature sensing experimental system are measured, and the performances of the system are experimentally verified. Results show that the distributed fiber quantum temperature sensing system can accurately locate the monitoring points, and the temperature measurement accuracy is high.