A beam homogenizer for digital micromirror device lithography system based on random freeform microlenses

Liu, Zhongyuan; Liu, Hua; Lu, Zifeng; Li, Qiankun; Li, Jinhuan

doi:10.1016/j.optcom.2019.03.049

Cited by 20 publications

(12 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In recent years, high-energy lasers have attracted much attention for their wide range of applications in laser illumination, − laser detection, etc. − Lasers exhibit a Gaussian distribution and strong coherence, requiring beam modulation for applications in photolithography, − laser projection, high-performance illumination, etc. − The realization of high-energy laser beam modulation often relies on extremely high threshold materials, which are conventionally used by silica glass. Among a bunch of approaches to beam homogenization, − microlens arrays (MLAs), due to their superior energy utilization, high flexible integration, and high homogeneity, are one of the most commonly used homogenizers. − However, due to the periodicity of the MLAs, interference between beamlets happens, and their related interference fringes appear in the obtained homogenized spots, seriously impacting the uniformity of the spots. To break the coherence between small beams, a continuous profile MLA with random aperture size and arrangement of sub-lenses is proposed, which is generally called random microlens arrays (rMLAs).…”

Section: Introductionmentioning

confidence: 99%

Random Silica-Glass Microlens Arrays Based on the Molding Technology of Photocurable Nanocomposites

Zhang

Song

et al. 2023

ACS Appl. Mater. Interfaces

Self Cite

View full text Add to dashboard Cite

Random microlens arrays (rMLAs) have been widely applied as a beam-shaping component within an optical system. Silica glass is undoubtedly the best choice for rMLAs because of its wide range of spectra with high transmission and high damage threshold. Yet, machining silica glass with user-defined shapes is still challenging. In this work, novel design and fabrication methods of random silica-glass microlens arrays (rSMLAs) are proposed and a detailed investigation of this technology is presented. Based on the molding technology, the fabricated rSMLAs with tunable divergent angles demonstrate superior physical properties with 1.81 nm roughness, 1074.33 HV hardness, and excellent thermal stability at 1250 °C for 3 h. Meanwhile, their characterized optical performance shows a high transmission of over 90% in the ultraviolet spectrum. The fabricated two types of rSMLAs exhibit excellent effects of beam homogenization with surprising energy utilization (more than 90%) and light spot uniformity (more than 80%). This innovative process paves a new route for fabricating rMLAs on solid silica glass and breaking down the barrier of rMLAs to broader applications.

show abstract

Section: Introductionmentioning

confidence: 99%

Random Silica-Glass Microlens Arrays Based on the Molding Technology of Photocurable Nanocomposites

Zhang

Song

et al. 2023

ACS Appl. Mater. Interfaces

Self Cite

View full text Add to dashboard Cite

show abstract

“…In the actual imaging, it will obviously produce partially clear image, partially blurred image, or even no image phenomenon, which will have a great impact on the illuminating effect. Therefore, improving the uniformity of diode laser by beam shaping is very important for the application of laser active illuminating field [11][12][13] . At the same time, as a circular beam source, the illumination field of view is also round, so the field of view will be missing in the four corners, which will result in incomplete collection of information.…”

Section: Introductionmentioning

confidence: 99%

Beam homogenization structure for a laser illuminator design based on diode laser beam combining technology

et al. 2023

View full text Add to dashboard Cite

With the rapid development of laser technology, laser as the light source of night vision illuminating can realize long-distance and clear imaging, which has been widely used in laser active illuminating field. A high-power diode laser with a wavelength of 808 nm was designed as the laser active illuminating source, and the output power of no less than 100 W was obtained by spatial beam multiplexing, polarization multiplexing, and high efficiency fiber coupling techniques. In view of the beam homogenization of illuminating source, a novel beam homogenization system based on waveguide is proposed in this work. A square spot with a horizontal divergence angle of 40°, a vertical divergence angle of 10°, and an illuminating power ratio of 4:1 was obtained by a collimating lens. Comparing with the traditional circular illuminating beam, the square illuminating beam can match the illuminating angle of CCD camera better, and the energy utilization rate is higher. In addition, by optimizing the structure of waveguide and collimating lens, the illuminating angle can be changed to meet the illuminating requirements under different conditions theoretically.

show abstract

“…This results in a narrow depth of field, making depth perception limited. In addition, when MLA is used for beam homogenization, the incident laser beam is divided into a series of sub-beams, which are superimposed on each other in the far field to eliminate the inhomogeneity between different sub-beams and form a homogenized spot [ 6 , 7 , 8 , 9 , 10 ]. When it is used for high coherence laser beam homogenization, the MLA with the same focal length will produce a periodic lattice phenomenon, resulting in the degradation of homogenization quality and so on.…”

Section: Introductionmentioning

confidence: 99%

Fabrication of Multifocal Microlens Array by One Step Exposure Process

Wei

Cai

et al. 2021

Micromachines

View full text Add to dashboard Cite

Microlenses can be widely used in integrated micro-optical systems. However, in some special applications, such as light field imaging systems, multifocal microlens arrays (MLA) are expected to improve imaging resolution. For the fabrication of multifocal MLA, the traditional fabrication method is no longer applicable. To solve this problem, a fabrication method of multifocal MLA by a one step exposure process is proposed. Through the analyses and research of photoresist AZ9260, the nonlinear relationship between exposure dose and exposure depth is established. In the design of the mask, the mask pattern is corrected according to the nonlinear relationship to obtain the final mask. The continuous surface of the multifocal MLA is fabricated by the mask moving exposure. The experimental results show that the prepared multifocal MLA has high filling factor and surface fidelity. What is more, this method is simple and efficient to use in practical applications.

show abstract

A beam homogenizer for digital micromirror device lithography system based on random freeform microlenses

Cited by 20 publications

References 19 publications

Random Silica-Glass Microlens Arrays Based on the Molding Technology of Photocurable Nanocomposites

Random Silica-Glass Microlens Arrays Based on the Molding Technology of Photocurable Nanocomposites

Beam homogenization structure for a laser illuminator design based on diode laser beam combining technology

Fabrication of Multifocal Microlens Array by One Step Exposure Process

Contact Info

Product

Resources

About