Excimer laser machining technology is based on photochemical mechanism. Excimer laser has the characteristics of short wavelength, high repetition rate, high single pulse energy, large output spot and uniform energy distribution. It has unique advantages in the field of precision and high efficiency microprocessing. Excimer laser micromachining can reduce the heat affected zone (HAZ) and effectively avoid cracks and other defects. It has a promising application prospect in the field of fine machining of materials. Research progress of excimer laser micromachining, and the application of excimer laser micromachining in the field of microelectronics integrated circuit packaging, micro-electro-mechanical system (MEMS) material processing and biological medicine are introduced. The development trend of excimer laser micromachining technology is summarized.

The testing of food pigment content is an indispensable part in food safety detection. Edible indigo blue and bright blue, two basic types of cyanine, are selected for research. A cyanine identification and quantitative analysis method based on absorption spectroscopy is proposed. By comparing the relationship between the molecular structure and characteristic peaks of these two types of cyanine and combining with electron transition theory, the difference of absorption spectra between them is analyzed. The quantitative analysis of bright blue pigment in multi-component system is carried out based on the difference of characteristic peaks, and the final model is established. Results show that the model has very high fitting degree, the linear regression coefficient reaches 0.99, and the average detection residual reaches 1.8 μg/ml.

In order to realize alignment of the large aperture catadioptric 355 nm laser receiving system, a local specific alignment method is put forward. Two-mirror system with wavelength of 355 nm, 632.8 nm mirrors and consistent mirror spacing uses 4D interferometer self-collimation debugging method. The lens group adopts self-collimation detection optical path debugging method composed of 355 nm laser and interferometer front lens. After alignment, the root mean square (RMS) of wave aberration in two-mirror system is 0.2026λ, which satisfies the design requirement of 0.2λ(λ is 632.8 nm). After the alignment of lens group, the difference between theoretical and self-collimation detection rear cut-off distances is in the range of design index tolerance. After the combination alignment of the two-mirror system and focusing lens group system, the focus of image and that of object are consistent, and the alignment of receiving system meets the design requirements. The proposed method reduces the difficulty of system alignment and shortens the system alignment cycle.

In order to reduce the film layer number and improve the reflection efficiency, a multi-layer film transmissivity calculation method is proposed. For the plane wave function of one-dimensional time-independent Schrdinger equation solution, the relation formula of film surface including incident and transmission wave amplitudes are obtained respectively based on the boundary conditions of thin film. The two formulas are connected by transmission and reflection waves inside the film. The relation including the transmission wave amplitude of the film layer is obtained, and that of the multi-layer film is obtained. According to the relationship between energy factor and refractive index, the film thickness is selected according to the matching principle, and the amplitude relation is transformed into an equation to calculate the multi-layer film transmittance. Four kinds of optical media are used to make film system, and the equation is numerically simulated and compared. Results show that the proposed method is feasible and the degenerative critical point of coating reflection effect is found. When the film layer number is 8, the film system reflectivity reaches 99.69%. If the traditional λ/4 film system is adopted, the film layer number must be 13 for reaching standard. It shows that efficiency of the proposed method is about 38% higher than that of the traditional method.

Entanglement percolation of quantum small-world networks in mixed state is investigated by means of generating function and entanglement swapping method. Based on theoretical calculation and numerical simulation, the relationship between normalized average component size and path length in small-world networks is analyzed. Results show that the small world networks have a larger average component size under the shorter paths in small-world network. It is further demonstrated that quantum small-world networks have larger aggregation and shorter average paths. It is found that the average component size increases with the increase of fidelity, and increasing the average degree of small-world networks can reduce the fidelity required for information delivery. The fidelity of maximum entangled states can be improved by entanglement swapping of mixed states, which shows that entanglement swapping can optimize the entanglement percolation in quantum small-world networks.

Based on time-division multiplexing technology, a quantum key distribution (QKD) system based on BB84 protocol is designed by using a single photon detector (SPD). The delay fiber with an increase of 6 m in turn is added to the different polarization signal optical path at the receiving end, which makes the arrival time of different polarization signal light to the SPD vary by 30 ns in turn. On the premise of accurate synchronization of signal and synchronous light, the detecting gate of different polarization signal light is numbered at the receiving end. The corresponding polarized photons are detected by SPD at different numbering gates. Security analysis results show that the QKD system can resist intercept-resent attack by eavesdroppers and ensure the security and reliability of communications. The QKD system is successfully applied to the 520 m QKD experiment. The key rate is 4.00 kbps and bit error rate is 1.5%.

In order to promote the automation of quantum communication platform, the software part in quantum key distribution (QKD) layer is designed and investigated. Based on experimental operation, the experimental process is encapsulated by writing friendly visual interface for beginners, which reduces the requirement of user’s programming level. The experimental optical path control in the platform is divided into three parts, MFC, Labview and FPGA. The three parts cooperate with each other to realize phase self-scanning which integrates control, scanning and judgment. Based on the designed optical path and software, quantum communication automatic operation platform is built, and the scanning stability is experimentally proved.

A bidirectional asymmetric control communication scheme in which seven-particle quantum entangled state is used as quantum channel is proposed. Alice transmits any single quantum bit (or any two quantum bits) to Bob and Bob transmits any two quantum bits (or any single quantum bit) to Alice via controlling of the supervisor Charlie. Bell base measurement is performed on final information transmitted by Alice and Bob, respectively. Von Neumann measurement is performed on Charlie’s results. The measurement results show that the proposed scheme can be realized perfectly. It provides an effective multi-information and high security method for the generation of multi-particle entanglement source transmission communication in quantum optics field.

Unbiased quantum walk corresponds to the classical asymmetric random walk in quantum world, and asymmetry is reflected by coin operation and conditional walk. The basic properties of unbiased quantum walk are characterized by calculating its position probability distribution, the probability and mean value back to the origin. Numerical results show that the recurrence property of unbiased quantum walk in one-dimensional chain is independent of the selection of coin initial state and whether the distribution after evolution is symmetric, but only related to asymmetric operation. One-dimensional classical random walk is recoverable only when it is distributed symmetrically. Different from classical random walk, it is one of the remarkable characteristics of quantum walk.

In order to achieve the safe transmission of protection setting in the coalmine high-voltage power grid, a protection setting transmission protocol based on quantum entanglement and channel self-checking is proposed. The protocol realizes the secure transmission of protection setting based on quantum entanglement properties, and consumes the less entangled particles by introducing the channel self-checking function. It establishes the quantitative relation between the consumed entangled particles number, number of routers that passes through and the transmission error rate of the packet. The simulation results show that compared with the setting transmission protocol based on quantum entanglement channel, it can complete the secure transmission of protection setting by consuming less entangled particles, whether the quantum communication network is stable or not. And when the quantum communication network scale increases, the proposed protocol consumes less entangled particles in transmission process, and it is more suitable for large-scale quantum communication network.

Based on the working principle and process of quantum navigation and positioning system, its optical signal transmission system is designed. The characteristics and selection of key components in the system are analyzed. Under the given parameters and expected performance index, the implementation scheme of an optical signal transmission system is designed combined with the characteristics of the key components including optical antennas, two-dimensional turntables, coarse tracking detectors, fast mirrors, fine tracking detectors in the acquiring-tracking-pointing (ATP) system, and single photon detectors in the HOM interferometer. It lays a foundation for the establishment of the simulation platform of optical signal transmission system, implementation of hardware system and further improvement of positioning accuracy in quantum navigation and positioning system.

Performance of orbital angular momentum (OAM) multiplexing communication system is inevitably degraded by the misalignment of OAM modes between the transmitter and receiver. Aiming at OAM state multiplexing system, a scheme used to reduce influences on system performance of the OAM misalignment between the transmitter and receiver is proposed by adopting multiple-input multiple-output (MIMO) equalization technology. The proposed scheme corrects or partially corrects the intermodal crosstalk of OAM state caused by misalignment of the transmitter and receiver ends. Numerical simulation results show that the proposed scheme can effectively reduce crosstalk between OAM modes of misaligned communication system, and the system bit error rate performance is improved. In the case of small lateral displacement and angular deflection, the system bit error rate can be increased by one or two orders of magnitude.

AuGe alloy has the characteristics of low contact resistance and good adhesion to GaAs substrate. It is widely used in metal/semiconductor (M/S) devices to form Ohmic contact. AuGe/Au material is deposited on GaAs surface, after rapid thermal annealing at different temperatures, the interfacial characteristics of Ohmic contact of the samples are analyzed by using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffractometer. With the increase of annealing temperature, the contact resistance shows a V-type trend. AuGe is partially decomposed. Au and Ge diffuse into the GaAs interface. Ga and As diffuse into the metal layer. The dark gray pores appear in the metal surface, and the main components are AuGa, AuGaAs etc. The bonding energy of Ge and Ga can increase 0.3～0.6 eV. The proportion of Ga3+ and Ge4+ increase, and the materials containing 10% Ge is selected as n-GaAs contact electrode. Excellent ohmic contact can be formed when the annealing temperature ranges from 380 °C to 420 °C.

Compared with graphene, black phosphorene has direct band gap and higher carrier mobility, and has higher stability compared with siliconene. These superior physical properties make it a great potential application value in the design of new quantum devices. By combining the unitary transformation with variational method, the ground-state energy formula of polaron and hole-phonon interaction system in monolayer black phosphorus on a polar substrate is deduced, and the band gap formula is obtained. The influence of temperature on the energy and band gap of polaron, hole and hole-phonon interaction system is investigated. Numerical calculation for black phosphorus on typical polar substrates shows that the energy and band gap of polaron (or hole-phonon system) increase with the increase of temperature or truncated wave vector, and decrease with the increase of phonon frequency, which indicates that the energy and band gap of polaron in black phosphene are directly related to the substrate material, and the influence of temperature on the properties of the substrate can’t be ignored.

Considering the weak-coupling of electrons and optical phonons, the expression of phonon mean number of weak-coupling polaron in triangular quantum well is derived by combining linear combination operator with unitary transformation. The linear relationship between electron-phonon coupling coefficient and phonon mean number is found. Results show that the influence of electron-phonon coupling strength on the phonon mean number can’t be ignored. Taking the semiconductor weak-coupled material as an example, the definite proportionality between the two materials is discussed. The result has certain theoretical guiding significance in the practical research.

Based on effective mass approximation and variational method, the actual conduction band binding potential in quantum well is approximated by the triangular potential considering band bending effect. The binding energy, Bohr radius and non-correlation probability of excitons in Cd1-xMnxTe/CdTe quantum wells are discussed and compared with square wells. The change of binding energy with well width and Mn component is given. Results show that the exciton binding energy increases first and then decreases with well width under the triangular potential approximation, which is similar to square well, but obviously smaller than square well. The difference between them increases with the well width and Mn component (barrier height). Correction of band bending should be considered in the research of related issues.

Theoretical formula of single-mode fiber bending loss coefficient change with bending radius is simulated. The bending loss coefficients of single-mode fiber winding in 1 circle under normal and high temperature and humidity conditions at 1550 nm are measured. The measured results are drawn into curves and compared with the theoretical curves obtained by simulation. The bending loss coefficients of fiber binding in 2, 3 or 4 circles under normal temperature, high temperature and humidity, salt mist and vulcanization are measured and compared with those in 1 circle. The difference is identified and the reason caused that is analyzed by comparison. Results show that the bending loss coefficients of the fibers with bending radium from 15 mm to 23 mm are approximately linear with the winding circle number in these four environments.