Microbial monitoring plays a key role in a wide range of fields spanning from medical diagnosis and food safety to fermentation and microbiological research. Microbial monitoring mainly include two aspects: the judgment of microorganisms and the measurement of the growth curve of microorganisms. Microbial growth usually correlate directly with certain indicators, such as DNA, pH, CO2 and OD, which provide a way for microbial monitoring. Among them, CO2 measurements have become the preferred approach because they prevent the interference of the dead bacteria and provide a more rapid and automatic answer. TDLAS technology has demonstrated high sensitivity, while being a simple yet mature technological structure for the detection of CO2 to provide a rapid and non-intrusive technique for microbial monitoring. It is of great significance to promote a new approach for monitor microorganisms. Progress of TDLAS technology in the field of microbial monitoring(growth) in recent years are reviewed.

Carbon dioxide (CO2) is not only an important greenhouse gas, but also a harmful asphyxiating gas. Therefore, the development of miniaturized, high-sensitivity concentration sensor of CO2 has great application requirements for detecting atmospheric CO2 by unmanned aerial vehicles, sounding balloons, and monitoring CO2 concentration in space-enclosed environments. An experimented setup based on 2.0 μm tunable semiconductor laser was established for the detection of CO2 concentration. The CO2 absorption line at 4989.97 cm-1 was chosen as the target line, and the CO2 gas sensing was carried out using micro-miniature off-beam quartz enhanced photoacoustic spectroscopy. By detecting the photoacoustic signals of a certain concentration of CO2 at different modulation frequencies and modulation amplitudes, the optimal modulation frequency and modulation amplitude of the system were obtained. The CO2 gas is detected under the optimized parameters, a detection limit of 142 μL/L is achieved, which corresponds to a normalized noise equivalent absorption coefficient of 3.37×10-8cm-1W/Hz1/2.

The color assessment cabinet has an important application in the fields of color printing, photography, dyeing and intelligent instruments. Krypton gas lamp is used as the A light source. By choosing 29 kinds of COB integrated packaging and high-power LED chips as the basic luminous unit the spectrum of B, C and D65 is simulated. Based on the measured linear normalized spectral power distribution data of each LED spectral model, a spectral matching algorithm based on genetic algorithm is proposed, and the proportion coefficient of each LED optical power is calculated through this algorithm. Based on the cold white LED optical power, the LED drive current control parameters are obtained from the linear fitting equation of the optical power and the driving current of each LED. The relative spectral difference of B, C and D65 spectra obtained from this method is 9.1%, 7.98% and 8.05%, respectively. The color rendering index of each fitting light source is 95.5234, 96.6841 and 99.2833, respectively. The color rendering index of the A light source obtained by krypton gas lamp is 99.3330. This design method can meet the requirements of the index very well.

According to the needs of investigation the illicit cultivation of opium poppy, the spectral reflectance of wheat, opium poppy, corn poppy and green bristlegrass in the wavelength range of 450～1000 nm was measured using a fiber optical spectrometer in the laboratory. Using the stepwise discriminant analysis method of SPSS statistical software, eight characteristic wavelength for distinguishing these four species of plants were obtained. The discriminant model is established with the selected characteristic wavelength point. The discriminant model takes poppy recognition error rate and the non-poppy recognition error rate as evaluation index. The variation of the recognition effect with the number of characteristic wavelength points and characteristic wavelength points was studied. The results showed that the wavelengths near the“red-edge”have an important influence on the identification of poppy and non-poppy. Using two combinations of the four characteristic wavelengths of 684.0, 706.4, 725.2, 919.2 nm or 684.0, 694.3, 706.4, and 725.2 nm, the poppy recognition error rate and non-poppy recognition error rate can be reduced to 0%.

The wave-particle duality is a basic concept in quantum mechanics and Anderson localization is an important phenomenon in condensed matter physics. Inspired by the wave-particle duality of photon in a two-arm interferometer, distinguishability D and visibility V are explored for an electron in one-dimensional random potential model with long-range hopping. We find that D2 is less than, equal to, and greater than V2 corresponding for delocalized, critical, and localized states, respectively. In this sense, the Anderson transition can be viewed as a transition from relatively more particle-like behavior to relatively more wavelike ones. This result gives a novel view to understand the wave-particle duality and Anderson localization.

An intelligent control system based on STM32 is designed aimed at prominent problem of the lack of integration of the laser control system and relatively single function. The system is equipped with a human-computer interaction interface based on EMWIN, which realizes the pulse laser touch screen control. Based on the system’s high-frequency clock, multi-channel pulse width modulation signal is generated to achieve high-precision control of the pulsed laser: the pumping voltage is 0～1000 V, which enables continuous adjustment. The pulse frequency is from 1 to 200 Hz, and the adjustment of multiple gear positions can be realized. The pulse width is 0～1000 μs, which is continuously adjustable with an accuracy of 20 μs. Both voltage and pulse width adjustments support fine-tuning and coarse tuning. The temperature sensor and ultrasonic ranging module are equipped on the system to monitor the laser operating temperature and divide the safe operating area in real-time.The signal measurement module is also introduced into the system with a sampling frequency of 1 to 100 kHz. The design realizes the integration of laser control and measurement, as well as process control and safety monitoring of laser operation.

The remote sensing equipment needs to be equipped with a high precision local clock source in order to synchronize with the clock of the satellite platform. The digital phase locked-loop design is a key technology of synchronization and frequency multiplication of the clock. Long period input signals and large frequency multiplication coefficient add more difficulties of the loop design from two different ways. Under the condition of second pulse synchronization and 10000 times frequency multiplication, a method of digital loop parameter algorithm was proposed. The response characteristics of the loop were analyzed by establishing the Z domain model and the approximate S domain model. The whole design was implemented by field programmable gate array. Experiments show that the design of the digital phase-locked loop can be locked in 5 input clock cycles, and the cumulative error is less than 0.1 ms per second during stable operation. In practical application, the digital phase locked loop can stabilize the output of the local clock to meet the needs of the remote sensing devices’ clock synchronization and frequency multiplication.

In order to resist the forgery attack of weak blind signature, a double weak blind signature scheme is proposed based on the quantum entanglement swapping principle. The scheme is completed by initializing, message blindness, double blind signature and verification by the sender, signer and verifier. The sender sends message after the blind to the signer. The signer produces blind signature with quantum controlled Not gate and performs Bell state measurement. The sender performs signature on the original message again with quantum measurement. The verifier verifies the two signatures separately and removes the blind to restore the original message. If a participant disputes the results of signature verification, the dispute is arbitrated by a trusted signer. Analysis shows that when the even digit of the key is constant 1, the method can not only resist external attack, but also prevent the sender from tampering effectively. It satisfies the unforgeable, non-repudiation, blind and traceability requirements of weak blind signature. The proposed scheme has broad application prospect in electronic commerce, electronic currency and other internet transactions.

Using the characteristics of the linear optical devices, such as polarization beam splitter(PBS), half-wave plate (HWP) and charge detector(CD), combing with the auxiliary single photon, the partially entangled two-photon system can be concentrated and the maximally entangled state can be obtained. Based on this protocol, it can be directly extended to the case of N-photon system. The pivotal issue of the success of the protocol is selecting the situations where two photons are emitted from different output modes when they pass through the first polarization beam splitter, meanwhile, the charge detector only contains one photon. For the cases where two photons are emitted from the same output mode, it can be used in the next round of entanglement concentration. The repeating concentration can achieve a higher success probability. In addition, the linear components used in this protocol reduce the difficulty in the experiment and have certain feasibility.

Tavakoli et al. used the cyclic property of the mutually unbiased basis and unitary transformations on it for the odd prime dimension, and designed a secret sharing scheme for d dimensional single quantum systems based on the mutually unbiased basis. Firstly, the class of standard orthogonal basis on even dimensional quantum systems is constructed, and relevant conclusions are given, and then an (N,N) threshold quantum secret sharing scheme based on the properties of the basis and unitary transformations on it is proposed. In contrast to Tavakoli’s scheme, the measurement efficiency of the proposed scheme has been doubled. And here are the corresponding basis, unitary matrix and related results about d=8 for illustration. Finally, the security of scheme related attacks is discussed.

In the process of quantum key distribution (QKD), privacy amplification can eliminate the leaked information of the key data in the QKD process itself and the key information that may be intercept by the eavesdropper, thus ensure the security of the generated quantum key. There are several schemes to realize privacy amplification algorithm based on CPU software. In order to improve the implementation security of this algorithm and the integration level, reduce the power consumption, the implementation of high speed Toeplitz matrix multiplication privacy amplification algorithm based on FPGA was researched. By using matrix block parallel computation, pipeline structure and other accelerated operation methods, the maximum bandwidth of secure key rate of this scheme is up to 20 Mbps when processing 256 kbits input key each time, and up to 5 Mbps when processing 1 Mbits input key each time。In addition, this scheme can adapt to input key length within 1 Mbits, and also adapt to the compress ratio between 0～1, which is conducive to the development of practical high-speed QKD system in the future.

Highly sensitive interferometer is essential to observation of many physical phenomena. Here a method to realize Ramsey interferometer by using stimulated Brillouin scattering effect is proposed. Two stimulated Brillouin scattering processes are involved in the method. The first one is to prepare the coherence phonons, in which the relative phase is achieved in the free evolution of the phonons, then the Ramsey fringes in the output field can be achieved with the assistance of the second stimulated Brillouin scattering process. Since the method is based on the mean values of the output photons, the observed Ramsey fringes are not sensitive to the noise. In addition, the scheme is feasible with current experimental technology.

Ca3(BO3)2 crystal is a new stimulated Raman scattering (SRS) crystal applied in the UV region. However, its SRS-active mode has not been deeply studied. The Raman spectrum of the crystal was investigated by the density functional theory (DFT) calculation. All of the Raman-active modes were assigned, and the SRS-active mode was confirmed to be attributed to the fully symmetric vibration of the BO3-3 group. The SRS-active modes of the CaCO3 and Ca(NO3)2 crystals also arise from the fully symmetric vibrations of planar triangular groups (CO2-3 and NO-3), but their intensities are much higher than that of Ca3(BO3)2. Electron density analyses showed that the intensities of the SRS-active modes of the Ca3(BO3)2, CaCO3 and Ca(NO3)2 crystals are positively correlated with the electronic conjugation effects of the BO3-3, CO2-3, and NO-3 groups. The DFT calculation showed that the isotopic effect of boron is negligible on the line-width of the Ca3(BO3)2 SRS-active mode. When the pump laser propagates along the crystallographic aH or cH axes, the crystal Raman scattering cross sections are almost the same.

The line shape excimer laser beam has been widely used in the industrial production of poly-silicon films. The large size amorphous silicon film prepared by plasma enhanced chemical vapor deposition is annealed by the line shape excimer laser beam output from the self-developed laser annealing equipment. The effects of energy density and irradiation times of the line shape laser beam on the crystallization of amorphous silicon films are researched. The crystallization volume fraction and the uniformity of the acquired large size poly-silicon film are discussed. The experimental results show that the crystallization threshold of the amorphous silicon film is 194 mJ·cm-2. The crystallization volume fraction increases with a linear factor of 0.3 first, and then decreases slowly. When the energy density is 432 mJ·cm-2, the crystallization degree reaches its peak. The crystallization volume fraction keeps stable when the number of irradiation is above 20. The crystallization volume fraction of the acquired large size poly-silicon film is 92.26% with the relative standard deviation of 1.56% in the right region under the overlap ratio of 93.7%, which are slightly better than the left region. This work gives references to the research of amorphous silicon film crystallization annealed by line shape laser beam and the nationalization of the line beam excimer laser annealing equipment.

In order to realize the rapid measurement of atmospheric horizontal visibility, the atmospheric horizontal visibility measurement system based on charge-coupled device (CCD) is designed, and the local weighted regression algorithm adopted in the system is investigated. The fitting lines of the local weighted regression and ordinary linear regression algorithms are compared by experiments, and the synchronous contrast measurement with the commercial NQ-1 visibility meter is carried out. Results show that the CCD measurement system with local weighted regression algorithm instead of ordinary linear regression algorithm can improve its correlation with the measurement data of visibility meter, and the correlation coefficient can increase from 85% to 96%. The real time comparison with the measurement data of the visibility meter shows that the error value of measurement system is reduced from 3 km to about 0.8 km. It can be found that the CCD measurement system using the local weighted regression algorithm basically meets the requirement of atmospheric horizontal visibility measurement.

The performance of CCD, such as readout noise, determines the final data quality of satellite X-ray detection payload. Commercial CCD sensor cannot be applied in space, neither in X-ray detection. The structure of an X-ray sensing CCD was explained, taking E2V space qualified product for example. Drive circuit met the time and voltage demand was designed with FPGA and an integrated drive circuit. CCD signal was amplified and filtered by a gain adjustable CCD signal process circuit. The calibration methods of gain and readout noise using Fe55 radioactive sources are also described. The measured gain of CCD and its support circuit is 5.1 e-/DN, and the readout noise is 37 e-.

Surface plasmon polariton (SPP) waveguides have been paid extensive attention for their unique properties, such as breaking the diffraction limit of light and providing subwavelength mode confinement. Surface plasmonic waveguides proposed before scarcely involve the tunability of the mode confinement and propagation loss by adjusting the geometric parameters. Here, a wedge-like surface plasmonic waveguide is proposed and its properties are investigated by finite element method (FEM). The wedge-like surface plasmonic waveguide features ultra-deep subwavelength mode confinement. The mode confinement and attenuation of the wedge-like surface plasmonic waveguide are controllable by adjusting the waveguide parameters, which makes the wedge-like surface plasmonic waveguide more flexible and could meet different requirements for mode area and propagation length at the same wavelength.

A membrane-free all fiber acoustic sensors based on a fiber-optic Fabry-Perot cavity is proposed and demonstrated. The acoustic response properties of the proposed sensor were exploited and the experimental results show that under the noise limit, the minimum acoustic pressure of the sensor can be detected up to 38.9 μPa/Hz1/2. Meanwhile, the sensing probe has a good temperature stability benefiting from its all-fiber structure. Compared with the sensors based on the acoustic sensing diaphragm, the proposed sensor possesses a simple structure, easy to make and has good linear response to acoustic pressure, which implies that such sensors can be widely used as microphone in applications of high acoustic pressure fields.

Investigation of relationship between the temperature in optical fiber and transmission characteristics is very important for the design and application of fiber composite low voltage cable(OPLC). A two-dimensional simulation model was established using COMSOL multi-physics simulation software to study the change of fiber axial stress with temperature, and the rationality of the model is verified by comparison with theoretical calculation. The stress elastic coefficient of quartz fiber was calculated theoretically and the transient temperature rise characteristics and thermal strain loss of the two kinds of optical fibers, acrylic and polyethylene, were analyzed by simulation based on the photo-elastic effect. The results show that the optical fiber with coating material of acrylic resin has smaller transient temperature rise in same time and lower loss at the same temperature. And its thermal strain loss increases linearly with increasing temperature in the range of 40°C to 250°C, with a maximum of 0.033 dB/km. From the viewpoint of transient temperature rise and thermal strain loss, the optical fiber with the coating material of acrylic resin is of more advantages in the application of OPLC.