A novel all fiber methane concentration detection system is constructed. The gas sensor was formed of the hollow core photonic bandgap fibers. The analysis was exhibited that FBGF inside light guiding mechanism and the diffusion characteristics of methane into the fiber core defect region. The design of the gas sensing cell was completed by multi segment PBGF connection coupled bending loop in the sensing chamber together, and then constructed the all fiber methane concentration detecting system. The regulation mechanism of distributed feedback fiber laser was brought into the system and the harmonic detection technology was used to realize the all optical fiber methane concentration detecting system optimization. The experimental result proves that the all fiber methane concentration detecting system composed of the sensing element can realize online real-time detection of methane concentration, and there is an approximate linear relation between the relative intensity and methane concentrations, the linearity up to 99.8%.

For the requirement of fast-response temperature of expendable ocean sensor, a new design scheme of optic fiber sensor was presented. Metal materials of different thermal expansion coefficients and the same tube structure with inner diameter d = 0.55 mm, length L = 9 mm were used for packaging FBG along the axis of a metal tube. And the temperature characteristics of the encapsulated Fiber Bragg grating (FBG) were experimentally studied. The theoretical calculation, simulation and the tests of the fast response properties were also described and analyzed in detail. The experimental results show that, the response time of the single-ended FBG packaged by a stainless tube is 47.1 ms, and the response time of the double-ended FBG packaged by a copper tube is 48.6 ms, which has increased by an order of magnitude than that of an ordinary optical fiber temperature sensor.

Establishing the model of FOG’s random drift and compensating in the filter is an effective method to improve the output precision of FOG. For traditional random drift of fiber optical gyroscope has some shortages like off-line, needing pre-process and the off-line models, which are usually not universal for environmental changing, a new modeling and filtering way is put forward. First, based on a large amount of measured data, the traditional off-line AR model is improved, and a new method to build the model of FOG’s random drift is studied. Then, the comparison is made between the traditional Kalman filter and H∞ filter in real time. The result demonstrates that improved AR model has much applicability and the performance of H∞ filter is better than Kalman filter. The minimum value of fitting accuracy is 91.6% and H∞ filter can improve the performance of filtering by almost 38.5% when analyzing ingle noise.

Acute cardiovascular disease is the leading killer of human health. Intravascular Photoacoustic (IVPA) imaging modality, which combines photoacoustic imaging and medical endoscopic technique, is expected to provide more reliable information about the vessel and plaques for the detection of vulnerable plaques and the interventional treatment of cardiac diseases. Till now, the study of the IVPA imaging has been still in its beginning stages. The study of the IVPA image reconstruction also mainly learns from the reconstruction algorithms of other mature imaging techniques. Based on the introduction of the IVPA imaging principle, two problems to be solved in IVPA image reconstruction are pointed out and some main reconstruction algorithms that can be applied to the IVPA image reconstruction are introduced and analyzed.

A method for endoscopic ultrasonic phased array imaging was proposed based on high-precision digital beamforming. Based on conventional digital beamforming, a new digital beamformer with A/D converter of high sampling rate was designed. Compared with the conventional digital beamformer, the delay precision of the new digital beamformer is upgraded to 1.4 ns from 8 ns. In this paper, we used the new digital beamformer to synthesize the ultrasonic signals received by the array elements. Then we utilized the digital quadrature demodulation circuit to realize envelope extraction of the synthetic ultrasonic signal. Finally, using iron wires in water tank as experimental sample, the experiment results show that using the digital beamforming technology, the peak sidelobe is effectively suppressed, and the lateral resolution and SNR are improved by 25% and 3.7 dB respectively.

Deep learning has been a hot spot in the area of machine learning, of which the convolutional neural network is an important component. Based on the deep convolutional neural network and the edge features of characters extracted by auto-encoder, a convolutional neural network of multi-input layers was proposed, which input layers consisted of multi-input with gradient of various directions. In the experiments of handwritten numbers recognition and pedestrian detection, the multi-input network has higher recognition rate compared with the traditional network structure, especially when the number of training time is fewer. This result also provides a proof that multi-input convolutional neural network performed better with appropriate preprocessing.

A spatial carrier phase detection technology based on deflection angle will be introduced in order to achieve dynamic phase simply and quickly in the measurement of digital speckle interference. Firstly, deflecting mirror was used to realize space carrier. Interference optical field was formed between object and deflection reference beams, as well as the information of carrier recorded. Then, three adjacent pixels on the CCD array were calculated to obtain interference phase information of the optical field. Finally, fast phase detection was implemented through a single speckle interference image. The method saves calculation times, simplifies the structure of the measuring system as well as algorithms, besides, and achieves the goal of fast phase detection compared with traditional phase detection technology.

A field calibration for laser scanning probe is put forward. Based on the model of camera calibration, the mathematical model of the laser plane is built. In order to get the more accuracy feature points, a new method using two alternate laser stripes which are not parallel to project on the chessboard is designed. The target is put in several different positions within the field of the camera vision aiming to get more feature points. All these feature points are fitted to an ideal plane after coordinate transformation. And the equation of the laser plane is obtained in camera coordinate. Experimental results indicate that the mean calibration error is less than 0.028mm. Using CMM to test the distance precision of the laser plane, the results show that the max distance error is 0.031mm. Experimental results indicate that the calibration technique has high accuracy and this method is suitable for field calibration.

Displacement measurement problem for dynamic target is widely studied. Research the testing and calibration model of the vertical optical axis binocular vision, deduce the lineup structure of the cameras and the positional relationship between the cameras and the target, and then establish non-contact vibration test system of dynamic target. Test system uses double area array CCDs to capture vibration images of the target. System extracts the target pixel position information to calculate the spatial coordinates of the target point, then according to the target pixel position changes in the whole process, to calculate the displacement variation in three dimensions. Experimental results show that the measurement accuracy is about 0.1 mm, and the maximum relative error is 1.73%, meeting the engineering test requirements. Measurement system has the features of compact, high accuracy and applicability, and achieving the purposes of intellectualized test and data analysis process automation. It can be popularly used to measure objectives’ three-dimensional space motion parameters and space gesture in engineering tests area, etc.

Noise sources of white-light interference system and their influence on the interferograms are introduced. The noise in white-light interferometer is complicated because it contains both the temporal and spatial component, which will seriously affect the quality of interferograms and as a result, and reduce the measurement accuracy. Traditional denoising methods based on single component processing are unable to completely remove the noise and cause the distortion of interferometric data. Using the three-dimensional noise model, three-dimensional characteristic of noise in white-light interference system is analyzed. Experiments show that the three-dimensional denoising method can move the temporal and spatial component of noise without causing the distortion of original data. In order to solve the problem of serious time consumption from three-dimensional denoising and reconstruction, corresponding parallel algorithm based on Graphic Processing Unit (GPU) is designed, which can easily realize the real-time reconstruction.

To improve the image quality of aerial photography, image motion compensation technology has become a hot scientific technology, and the V/H of carrier aircraft is an important parameter of image motion compensation technology. This paper comprehensively describes a new method of the accurate measurement of V/H based on image matching, and this method use the image motion compensation formula reversely to measure the instantaneous V/H, realized the digital and miniaturization of the measurement. The relative error of this method can be reduced to 0.5%. The new method can effectively improve the accuracy of image motion compensation.

The gravity deformation of the lenses is controlled by force mounting in their under surface margin. Finite Element Analysis (FEA) method is used to analyze the relationship between the lens surface’s non-spherical deformation and the compensating force. The deformation data are fitted to Zernike coefficients. Compared with the wavefront of projection optics before and after compensation, the influence of gravity deformation can be evaluated. The results show that the max non-spherical deformation RMS is decreased from 50.877 nm to 26.675 nm because of compensating force. However, the max wavefront error-root mean square value of projection optics is increased from 0.041λ to 0.055λ. Although the gravity deformation can be controlled by the compensating force efficiently, the wavefront aberration of projection optics is increased. The gravity deformation cooperation of the lenses should be considered so as to achieve better wavefront.

In recent years, the laser display is the tendency of the display technology. A new kind of illumination system is proposed for laser light source, which consists of laser array light source, improved Cassegrain optical system, fiber, laser diffuser and 4f-relay system. In order to obtain efficient and uniform illumination distribution, the light from the laser is collected by the improved Cassegrain optical system and then coupled into the fiber where it’s been mixed and uniformed. Then the beam is collected on the 0.61-inch LCOS chip through the 4f-relay system after being shaped by the laser diffuser. The system could achieve high brightness illumination because the fiber can be bent and combined, and the optical extension is evaluated based on optical extend. Finally, the designed system is ray tracing simulated in optical software to verify the feasibility of the method.

For the 2 μm resolution lithography, in the lithography system with the digital micro-mirror device as space light modulator, we design a high resolution and large-area projection lens with new asymmetric structure assembly and fewer lens. By using ZEMAX optical design software to simulation-design and optimize, the results show that its optical path difference for entire field of view is less then λ/10, its distortion is less than 0.02％, its image space numerical aperture NA=0.158, its resolution is 2μm, its paraxial reduced ratio is β=-0.217. This can effectively reduce the DMD grid effect for the digital space mask and meet all kinds of requirement for projection lens optical system. Finally, we analyze the tolerance of the design results. By amending a few default tolerances and using the Monte Carlo method, it is verified the assembling and fabricating feasibility of this kind of new structure projection lens.

A design method for Light-emitting Diode (LED) Compound Elliptical Concentrator (CEC) is proposed based on optical extent, in order to satisfy specific emergent angle and high efficient illumination in short distance. Firstly, the CEC generatrix equations are derived according to the optical properties of LED light source and the optical extent conservation theory in non-imaging optics. Then the front and rear surface types are analyzed in the light of the edge-ray principle and the ray tracing theory in geometrical optics. Finally, the designed system is ray tracing simulated in optical software ZEMAX. The results show that, the emergent angle is 51.6° and the light energy utilization efficiency reaches 69%, in the scope of 8 mm×8 mm detector that is 4mm away from the CEC exit aperture. The reasonableness of the method is proved by comparing the simulation results with the theoretical calculation. Using the small size-concentrator is an effective way to realize system’s miniaturization and simplification.