Optical design and simulation of a compact multi-aperture camera based on a freeform microlens array

Chen, Wenhu; Zhang, Xiaodong; Liu, Xianlei

doi:10.1016/j.optcom.2014.10.029

Cited by 18 publications

(4 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In these applications, the used freeform surface is generally a continuous and smooth surface characterized by different analytical functions. Additionally, a microfreeform-prismbased lens array is employed in the artificial compound eye [18][19][20] and can realize a large field of view using multiple imaging channels with lower distortion. Each imaging channel is a microfreeform-prism lens represented by XY polynomials or Zernike polynomials to correct the aberration in the corresponding channel.…”

Section: Applications Of Different Types Of Opticalmentioning

confidence: 99%

Review of optical freeform surface representation technique and its application

Chen

et al. 2017

Opt. Eng

View full text Add to dashboard Cite

Abstract. Modern advanced manufacturing and testing technologies allow the application of freeform optical elements. Compared with traditional spherical surfaces, an optical freeform surface has more degrees of freedom in optical design and provides substantially improved imaging performance. In freeform optics, the representation technique of a freeform surface has been a fundamental and key research topic in recent years. Moreover, it has a close relationship with other aspects of the design, manufacturing, testing, and application of optical freeform surfaces. Improvements in freeform surface representation techniques will make a significant contribution to the further development of freeform optics. We present a detailed review of the different types of optical freeform surface representation techniques and their applications and discuss their properties and differences. Additionally, we analyze the future trends of optical freeform surface representation techniques.

show abstract

Section: Applications Of Different Types Of Opticalmentioning

confidence: 99%

Review of optical freeform surface representation technique and its application

Chen

et al. 2017

Opt. Eng

View full text Add to dashboard Cite

show abstract

“…In 2014, Fang Fengzhou et al designed a free-form surface microlens array suitable for multi-aperture cameras. The 3×3 microlens array has a field of view of 24°×24° and a thickness of only 2 mm [6] . In 2015, Jens Dunkel et al developed a multi-aperture imaging system including a two layer free-form surface lens array.…”

Section: Introductionmentioning

confidence: 99%

Design of infrared sub-aperture polarization imaging system based on freeform surface

Chen

Xie²,

Yang³

et al. 2022

Optical Design and Testing XII

View full text Add to dashboard Cite

Infrared polarization imaging can achieve faster perception speed and higher identification accuracy, which has been widely applied in diverse areas such as space remote sensing, biomedicine, and object detection. Limited by the aperture of the lens, the single-aperture imaging system can hardly meet the needs of high-resolution and multi-polarization imaging simultaneously. Aiming at achieving the properties of high-resolution, high-integration, and multi-channel performance, a sub-aperture infrared polarization imaging system based on freeform surfaces is proposed and demonstrated. The general scheme of the polarization imaging system mainly consists of a common aperture structure, a sub-aperture imaging group, and a relay imaging group. To compress the beam aperture, a Kepler telescope configuration is employed to build up the imaging objective. The field diaphragm is set at the primary image plane to effectively eliminate stray light. Polarizers with different orientations are added to the split aperture imaging group to form four polarization state channels. To reduce the assembly errors of the sub-aperture system, a freeform surface lens is utilized to replace the lens group in the multi-channel. The freeform surface profile uses the "XY polynomial" with eight coefficients. A diaphragm array is arranged on the front surface of the sub-aperture system, which is used to avoid the intersection between the image planes of different channels. To match with the cooled detector, the relay imaging group is designed as a finite conjugate structure with a magnification of -0.44×. The structure allows for simultaneous imaging of four infrared polarization states with the same system, and the MTF of each channel at 33lp/mm is higher than 0.45. Our research satisfies both miniaturization and engineering application requirements.

show abstract

“…Optical freeform surfaces are widely used in space optics, projection optical systems [ 1 , 2 , 3 ], medical endoscope systems [ 4 , 5 , 6 ], and other fields because of their complex surfaces and multiple degrees of freedom. With the increasing demand for freeform surfaces in the aerospace industry, national defense and the military, precision instruments, and other modern cutting-edge technology fields, a variety of freeform surfaces with a high degree of curvature and steepness have been proposed, and the accuracy of freeform surface manufacturing in various fields has become higher [ 7 , 8 ].…”

Section: Introductionmentioning

confidence: 99%

Modeling and Analysis of System Error for Highly Curved Freeform Surface Measurement by Noncontact Dual-Axis Rotary Scanning

Zhu

Fang

et al. 2021

Sensors

Self Cite

View full text Add to dashboard Cite

Profile measurement is a key technical enabler in the manufacturing of highly curved freeform surfaces due to their complex geometrical shape. A current optical probe was used to measure nearly rotary freeform surfaces with the help of one rotation axis, because the probe needs to measure along the normal vector of the surface under the limitation of the numerical aperture (NA). This kind of measuring system generally has a high cost due to the high-precision, multi-axis platform. In this paper, we propose a low-cost, dual-axis rotation scanning method for a highly curved freeform surface with an arbitrary shape. The optical probe can scan the surface profile while always keeping consistent with the normal vector of the measuring points with the help of the double rotation axis. This method can adapt to the changes in curvature in any direction for a highly curved freeform surface. In addition, the proposed method provides a system error calibration technique for the rotation axis errors. This technique can be used to avoid the dependence of the measuring system on the high-precision platform. The three key system errors that affect the measurement accuracy such as installation error of the B-axis, A-axis, and XZ perpendicularity error are first analyzed through establishing an error model. Then, the real error values are obtained by the optimal calculation in the calibration process. Finally, the feasibility of the measurement method is verified by measuring one cone mirror and an F-theta mirror and comparing the results to those obtained using commercial equipment. The maximum measurable angle of the system is ±90°, the maximum measurable diameter is 100 mm, and the measurement accuracy of the system reaches the micron level in this paper.

show abstract

Optical design and simulation of a compact multi-aperture camera based on a freeform microlens array

Cited by 18 publications

References 12 publications

Review of optical freeform surface representation technique and its application

Review of optical freeform surface representation technique and its application

Design of infrared sub-aperture polarization imaging system based on freeform surface

Modeling and Analysis of System Error for Highly Curved Freeform Surface Measurement by Noncontact Dual-Axis Rotary Scanning

Contact Info

Product

Resources

About