wavefront coding technology (WFC) is a computational photography technique that significantly extends a system's depth of field (DOF) while mitigating the impact of aberrations and the environment. A freely insert...
详细信息
wavefront coding technology (WFC) is a computational photography technique that significantly extends a system's depth of field (DOF) while mitigating the impact of aberrations and the environment. A freely inserted wavefront coding microscopy system that realizes high-resolution imaging with large DOF in a wide field of view (FOV) is proposed. On the basis of a designed large DOF microscopy system, an adaptive genetic algorithm is developed to interactively analyze, design, and optimize the phase mask and its effects on the system. The algorithm adaptively adjusts the parameters for selection, crossover, and mutation. Furthermore, it reconstructs the optimization function while considering processability, thereby efficiently and accurately selecting phase mask parameters. The phase mask is prepared and integrated into the system with a freely inserted fixture, which provides flexibility and ease of operation. wavefront encoding/decoding experiments demonstrate that the system can extend the DOF by approximately +/- 13 times in a large FOV, while slightly decreasing the resolution from 6.20 mu m to 7.81 mu m, and mitigating aberrations and FOV effects. The integrated phase mask does not influence the design of the optical system, is universal, and simplifies the system's structure. This provides advantages in applications such as biological microscopes, endoscopes, and drones, which have strict sample and environmental requirements.
This paper proposes a simple method to achieve the optical transfer function of a circular pupil wavefront coding system with a separable phase mask in Cartesian coordinates. Based on the stationary phase method, the ...
详细信息
This paper proposes a simple method to achieve the optical transfer function of a circular pupil wavefront coding system with a separable phase mask in Cartesian coordinates. Based on the stationary phase method, the optical transfer function of the circular pupil system can be easily obtained from the optical transfer function of the rectangular pupil system by modifying the cut-off frequency and the on-axial modulation transfer function. Finally, a system with a cubic phase mask is used as an example to illustrate the way to achieve the optical transfer function of the circular pupil system from the rectangular pupil system.
wavefront coding (WFC) enables the depth of field of incoherent optical systems to be extended. This method involves a cubic-phase plate in the system yielding a blurred image nearly invariant to defocus. In visual op...
详细信息
ISBN:
(数字)9781510613843
ISBN:
(纸本)9781510613843;9781510613836
wavefront coding (WFC) enables the depth of field of incoherent optical systems to be extended. This method involves a cubic-phase plate in the system yielding a blurred image nearly invariant to defocus. In visual optics there is a big interest in improving solutions for two different problems: Presbyopia correction and high resolution retinal images with low cost devices. In this work we will show how the use of cubic phases in contact lenses can be an alternative to multifocal lenses and how WFC technique can be applied to record high resolution retinal images reducing the complexity of the actual systems.
Under reverse light conditions, the incident light energy from the target is substantial, leading to saturation in existing detectors. This saturation can cause damage and impair the detectors, resulting in an inabili...
详细信息
ISBN:
(纸本)9798350325621
Under reverse light conditions, the incident light energy from the target is substantial, leading to saturation in existing detectors. This saturation can cause damage and impair the detectors, resulting in an inability to effectively perceive the potential threat of reverse light. Currently, installing lens covers on the detectors is the primary approach, but it has limitations in terms of detection range and applicability. To address these challenges, this paper proposes an optical detection method based on wavefront coding, leveraging its directional dispersion, strong light suppression, and near-lossless restoration characteristics. This method enables the detection and verification of backlight targets. Additionally, a design optimization method for an aspherical phase mask is introduced. By incorporating the surface function in the calculation, the point spread function of different surface phase masks is derived. This allows for the advanced prediction of the static model of the wavefront coding optical imaging system after the insertion of the phase mask. Experimental verification demonstrates that the aspherical phase mask can suppress high-light targets by over 200 times and successfully restore the image. This novel approach surpasses the limitations of traditional lens covers by effectively perceiving and addressing reverse light conditions.
wavefront coding involves the insertion of an asymmetric refractive mask close to the pupil plane of an imaging system so as to encode the image with a specific point spread function that, when combined with decoding ...
详细信息
ISBN:
(纸本)0819455652
wavefront coding involves the insertion of an asymmetric refractive mask close to the pupil plane of an imaging system so as to encode the image with a specific point spread function that, when combined with decoding of the recorded image, can enable greatly reduced sensitivity to imaging aberrations. The application of wavefront coding has potential in the fields of microscopy, where increased instantaneous depth of field is advantageous and in thermal imaging where it can enable the use of simple, low-cost, light-weight lens systems. It has been previously shown that wavefront coding can alleviate optical aberrations and extend the depth of field of incoherent imaging systems whilst maintaining diffraction-limited resolution. It is particularly useful in controlling thermally induced defocus aberrations in infrared imaging systems. These improvements in performance are subject to a range of constraints including the difficulty in manufacturing an asymmetrical phase mask and significant noise amplification in the digitally restored image. We describe the relation between the optical path difference (OPD) introduced by the phase mask and the magnitude of noise amplification in the restored image. In particular there is a trade between the increased tolerance to optical aberrations and reduced signal-to-noise ratio in the recovered image. We present numerical and experimental studies based of noise amplification with the specific consideration of a simple refractive infrared imaging system operated in an ambient temperature varying from 0degreesC to +50 C. These results are used to delineate the design and application envelope for which infrared imaging can benefit from wavefront coding.
We have implemented an extended depth of field optical system by wavefront coding with a micromachined membrane deformable mirror. This approach provides a versatile extension to standard wavefront coding based on fix...
详细信息
ISBN:
(纸本)9781628414257
We have implemented an extended depth of field optical system by wavefront coding with a micromachined membrane deformable mirror. This approach provides a versatile extension to standard wavefront coding based on fixed phase mask. First experimental results validate the feasibility of the use of adaptive optics for variable depth wavefront coding in imaging optical systems.
wavefront coding is a hybrid optical-computational technique that makes use of a phase modulating element in conjunction with a deconvolution algorithm to extend the depth of focus of imaging systems. The phase mask c...
详细信息
ISBN:
(数字)9781510629028
ISBN:
(纸本)9781510629028
wavefront coding is a hybrid optical-computational technique that makes use of a phase modulating element in conjunction with a deconvolution algorithm to extend the depth of focus of imaging systems. The phase mask codes the wave-front in such a way that the point-spread function do not change appreciably as a function of defocus. In this work, the modulation is introduced by phase masks in the shape of a subset of Jacobi-Fourier polynomials. We will show, by both numerical simulations and experiments that the Jacobi-Fourier polynomial phase masks are good candidates for highresolution images under noise presence.
The point spread function(PSF)caused by a wavefront coding system with a cubic phase mask has big side-lobes which leads to bad image *** paper proposes a novel apodized cubic phase mask to suppress the side-lobes of ...
详细信息
The point spread function(PSF)caused by a wavefront coding system with a cubic phase mask has big side-lobes which leads to bad image *** paper proposes a novel apodized cubic phase mask to suppress the side-lobes of the *** annealing algorithm is used to optimize the cubic and the truncation parameter of the phase *** system with the novel phase mask has better performance in the modulation transfer function(MTF)especially in low-and-medium spatial frequency *** simulation results show that the restored images with the novel phase mask are superior to the one with the classic cubic phase mask in contrast and ringing *** experimental results show that the side-lobes of the PSF are suppressed by using the apodized cubic phase mask.
By applying the wavefront coding technique to an optical system, the depth of focus can be greatly increased. Several complicated methods, such as Fisher Information based method, have already been taken to optimize f...
详细信息
By applying the wavefront coding technique to an optical system, the depth of focus can be greatly increased. Several complicated methods, such as Fisher Information based method, have already been taken to optimize for the best pupil phase mask in ideal condition. Here one simple point spread function (PSF) based method with only the standard deviation method used to evaluate the PSF stability over the depth of focus is taken to optimize for the best coefficients of pupil phase mask in practical optical systems. Results of imaging simulations for optical systems with and without pupil phase mask are presented, and the sharpness of image is calculated for comparison. The optimized results showed better and much more stable imaging quality over the original system without changing the position of the image plane.
Color coding has been experimentally demonstrated to be able to extend the depth of field (DoF) of an imaging system in single snapshot. A numerical model is adopted in this paper to quantitatively characterize its im...
详细信息
Color coding has been experimentally demonstrated to be able to extend the depth of field (DoF) of an imaging system in single snapshot. A numerical model is adopted in this paper to quantitatively characterize its imaging properties (strehl ratio, point spread function and modulation transfer function). To improve the system's performance under nonuniform spectrum, we proposed to introduce wavefront coding into the system. Numerical results show that wavefront coding acts as an average filter of the spectrum, so that it is able to get an almost invariant MTF across the focal line even under nonuniform spectrum, which is desirable in many applications.
暂无评论