Based on the introduction of sensing principles of short-period fiber Bragg grating (FBG) and micro-nano fiber Bragg grating (MNFBG) refractive index and how to improve FBG refractive index sensing sensitivity, the research progress of two refractive index sensing technology schemes such as etching and polishing methods are described in detail. The advantages and disadvantages of the two schemes are compared and analyzed. The research status of micro-nano fiber and fiber grating used in refractive index sensing is summarized. The technology problems and solution schemes on current research are proposed and the development trend of FBG refractive index sensing technology is forecasted, which provide a reference for further research on refractive index sensing based on fiber grating devices.

Beam axial scanning has been widely applied in the fields of three-dimensional optical imaging and optical material production. However, the existing beam axial scanning methods all have their own drawbacks such as low scanning speed, limited scanning range and damage on the activity of biological samples. Based on focal spot manipulation theory and through performing illumination beam phase encoding, the relative axial position of the focal spot is changed to realize beam axial scanning. The feasibility of the method is verified through simulation calculation. Simulation results show that the scanning method has better linearity and linear fitting factor R2 is 0.993 9. Without mechanical movement, the method has high scanning accuracy, little influence on biological samples, and has potential ability to be well applied in the area of related scientific researches.

According to the detecting requirements of double band Infrared detecting equipment in different bands and the double band radiation characteristics of flaring light pipe, unmanned aerial vehicle (UAV) equipped with flaring light pipe as low-level moving target is proposed. Same target meeting double band testing requirements is realized. Through designing UAV fairway distance and heading, testing projects meeting the requirements such as action distance and target data accuracy are realized in the same flight. Target track real value accuracy is analyzed deeply. The correlation and setting methods of relative parameters such as fairway, heading and distribution stations under different conditions are summarized to provide full technology preparation and choosing space for the testing project.

Impulse radio ultra-wide band (IR-UWB) is one of the most classical ultra-wide band (UWB) implementation schemes. The generated pulse width is at sub-nanosecond level, which can take advantage of baseband narrow pulse sequence with low duty ratio to carry signals. And the IR-UWB generator with the advantages of small volume, light weight, low noise, good tunability and anti-electromagnetic interference may generate pulse signals flexibly. Five IR-UWB pulse signal optical generation methods such as IR-UWB pulse signal generated by optical pulse compression, IR-UWB pulse signal based on phase modulation and polarized beam splitting system (BPS), IR-UWB pulse signal based on phase modulation and generated by apodized fiber Bragg grating (AFBG), IR-UWB pulse signal generated by optical band-pass filter and IR-UWB pulse signal generated by semiconductor laser are researched. By contrasting research results in China and foreign countries in this field, IR-UWB optical generation methods hereinbefore are discussed and summarized and the advantages and disadvantages of the methods are compared.

The theories of frequency shift and beat frequency generated by acousto-optic interaction are more perfect, but the detailed changing rules are not described. Based on experiments and with a high frequency detector, a confocal scanning interferometer and a spectrum analyzer, through researching the beat frequency phenomena of Raman-Nath diffraction point, the beat frequency phenomena generated by acousto-optic interaction is directly shown. The generation principle of beat frequency is analyzed. The generation rule of beat frequency is summarized and elements such as generation condition are explored.

Super-continuous spectrum in sapphire fiber acted by femto-second lasers is researched. A femto-second laser with 50 fs pulse width is chosen as a pumping light source and a 9 cm sapphire fiber as nonlinear medium. The super-continuous light sources in Infrared and visible band can be obtained at sapphire fiber output terminal when laser center wavelength is 1 200 nm, 1 300 nm, 1 400 nm and 1 500 nm respectively. Semiconductor saturable absorber mirror (SESAM) is added to experimental devices to get better super-continuous light source output in visible band. A resonator is made up of fiber terminal surface and SESAM. And multi-acted fiber is realized by SESAM feedback. The results show that 460~780 nm flat and stable super-continuous light source output in visible band is obtained.

The physical model of three-dimensional pulse laser irradiation aramid fiber composites is established by finite element software. And the temperature field distribution and the change rules of aramid fiber composites are obtained. The results show that with the increasing of laser power density, the temperature of aramid fiber composites rises gradually. The temperature value of the composites acted by different laser power density is the maximum at facula center, and it decreases with the increasing of the distance between different points and center point. For verifying numerical analysis model and researching the thermal damage rule of aramid fiber composites, nanosecond pulse laser irradiation aramid fiber composites with different power density is chosen during the experiment. The research results show that numerical simulation temperature better accords with experimental temperature and the maximum relative error is 12.49%. With the increasing of laser power density, the coking and carbonized areas of aramid fiber composites increase gradually and the melt depth will gradually deepened.

During optical measurement data processing, multinomial fitting principle is used to estimate parameters and calculate interpolation, which brings higher block error. According to the problem, recursion spline least square fitting method is proposed. Based on the characteristics of flight target track datum, and with the spline function and recursion idea, the simulation calculations show that the accuracy and calculation speed of the fitting can be improved by the method. It has higher practical value.

Thickness is an important influencing factor in liquid non-destructive testing (NDT). Wavelet transform as an important signal processing means has many advantages such as dynamic error threshold determination and multi-scale wavelet transform de-noising. The obtained data are performed multi-level wavelet decomposition and threshold processing of soft threshold through constructing a NDT platform. Comparing with traditional filtering method, the advantages of wavelet transform used in laser NDT are verified. Experimental results show that wavelet transform in laser NDT has better denoising effect and has great significance for liquid NDT on public.

From the relative definition and phenomena of glare effect, the forming base of glare effect is analyzed, and the action variation express of glare effect is determined. A glare effect action mechanism model is built to provide a theory analysis method for the application of glare effect.

Satellite tool kit (STK) with accurate simulation performance is a kind of advanced satellite system analysis software used in all phases of aerospace engineering widely. But STK integrated with application program efficiently is a very difficult problem. A method for the integration of STK with MFC is proposed by using STKX module, and incorporated programming procedure is interpreted in a target identification simulation example. Applicable operation results show that private computer (pc) simulation platform consisted of 8 PCs is in effective and stable operation state. Flexibility and efficiency are improved greatly by the method of integrating STK with MFC.

Based on simple physical model and matrix optical method, the focusing adjustment formulas of plane wave, spherical wave and Gaussian beam from laser optical transmitting system are deduced. And the focusing adjustment properties of the three kinds of waves are calculated and analyzed. During plane wave focusing adjustment, with the decreasing of focusing adjustment quantity absolute value, focusing distance increases. When focusing adjustment quantity closes to zero, the increasing speed of focusing distance is faster. During spherical wave focusing, collimation emission status with infinity focusing distance exists. The emission wave beam becomes divergent if focusing adjustment quantity is over the values corresponding to the state. At the same time, with the increasing of the distance between spherical wave curvature center and secondary mirror, the focusing adjustment quantity corresponding to collimating emission state move right and close to zero. During Gaussian beam focusing and with same focusing adjustment quantity, there is an obvious difference between Gaussian beam waist and plane wave focus position in far distance. The difference can be reduced through increasing the waist width of incoming Gaussian beam and the expanded beam ratio of laser optical transmitting system and choosing shorter wavelength optical beam.

Aiming at the great error of positioning and measurement of a shipborne theodolite caused by vessel shaking, a high precision solution for correcting the vessel-shake error is proposed. Vessel-shake attitude angel and GPS local baseline positing information are measured by an inertial navigation system. The shipborne theodolite data of real-time position and measuring angle are performed to vessel-shake error correction. And the influence on measuring angle accuracy from position error is researched. According to the data error comparison analysis before and after correction, the exterior trajectory measuring accuracy of sea-based measurement and control equipments is improved. Experimental results show that the method is simple and applicable. The corrected accuracy can meet the requirements, and can be applied widely.

UV absorption full spectroscopy with many features such as accurate, reliable, simple, fast and practical is used to measure the nitrate concentration in seawater. UV absorption full spectroscopy is used to test nitrate, bromide, chloride, nitrite, turbidity and their mixed solutions with nitrate at 200~370 nm. The UV absorption spectrums of the substance influencing on seawater nitrate measure is analyzed. Through comparing and analyzing nitrate, the UV absorption spectrum features of nitrate and interfering substances and absorbance changed with wavelength are obtained. The linear fitting curve of nitrate concentration and absorbance show that they have good linear relationship and the accuracy of the experiment is verified. The results show that UV absorption full spectroscopy can be used to measure nitrate in seawater.

Cat-eye effect widely existing in electro-optical imaging system is researched. According to the retro-reflection property of a cat-eye target, a mathematical model under different echo wave intensity is established. Based on the model and TracePro software, the cat-eye effect of a typical target with different laser emission distance, lens focal shift and incident angel is simulated and analyzed. Results show that theoretical calculation accord with the simulation results, so it can be used to guide laser active detection system design in the future.

For getting more real Infrared images, a new method of retrieving Infrared images using low-level images is proposed. Firstly, low-level images with different material properties are classified according to ground material properties using improved K-means clustering algorithm. And then, the total radiant energy into simulation Infrared thermal imaging system in special bands is calculated. And simulation Infrared images are obtained through simulating sensor imaging principle. The generation of Infrared scene sequence images in some area is finished with the algorithm and real measurement environment meteorological parameters. Experimental results show that the sequence images generated with the method basically accord with the change rules of real Infrared images, so an effective way is provided for low-level images simulation generation.

According to the planning problem of multi-layer level and multi node passive optical network (PON) in distribution power supply optical communication network, multi-layer level cycle inheritance stacked genetic algorithm based on basic genetic algorithm is proposed for the first time. The outer layer distribution optical network is used to inherit inner layer network gene to choose adaptation function in the layer network. The layer level optical distribution optimization problem of multi-layer level PON is resolved by the algorithm. Simulation results show that the algorithm is feasible and the topology optimization of four-layer level network with star structure is realized. The optimized network obtains the best star structure network topology and the communication construction cost is reduced.

The dynamical behavior of controlled Gibbs laser system is researched. Gibbs laser system model is introduced at first. The images from Lyapunov exponent of Gibbs laser system changing with incident light intensity parameters and the relationship curve of the relative system state variable and incident light intensity parameters are given. The influence on system dynamical behavior from feedback signal intensity is simulated further. The results show that nonlinear effects such as double periodic bifurcation, periodic combination and chaos through regulating feedback signal strength exist in the system.