A doublet microlens array for imaging micron-sized objects

Abstract

We present a high-numerical aperture, doublet microlens array for imaging micron-sized objects. The proposed doublet architecture consists of glass microspheres trapped on a predefined array of silicon microholes and covered with a thin polymer layer. A standard silicon microfabrication process and a novel fluidic assembly technique were combined to obtain an array of 56 μm diameter microlenses with a numerical aperture of ~0.5. Using such an array, we demonstrated brightfield and fluorescent image formation of objects directly on a CCD sensor without the use of intermediate lenses. The proposed technology is a significant advancement toward the unmet need of inexpensive, miniaturized optical modules which can be further integrated with lab-on-chip microfluidic devices and photonic chips for a variety of high-end imaging/detection applications.

High Numerical Aperture Hexagonal Stacked Ring-Based Bidirectional Flexible Polymer Microlens Array

“…Recently, MLAs (NA: < 0.56) were fabricated with laser ion-beam patterning and direct laser ablation. 1,29 Laser ablation based holographic laser interference lithography has been used to efficiently produce a surface-relief MLA. 30 This approach is fast, eliminates complex and tedious pre-/posttreatment of samples, is cost-effective, and does not require high technical expertise.…”

MRT letter: Micro‐ to nanoscale sample collection for high throughput microscopy

“…With holographic scanning, alternatively, a hologram is created to hold an array of focal spots at the sample plane (Wu et al, 2010), wherein the chromatic properties of the holographic focusing element used to scan the focus grid axially (Wu et al, 2011). Recently, another approach that uses an array of high numerical aperture (NA) refractive microlenses has been reported (Orth and Crozier, 2012), which contrasts with other geometries where each microlens relays a widefield image (Tripathi and Chronis, 2011).…”

73‐4L: Late‐News Paper: Wavelength‐independent Electrically Tunable Microlens Array with a Chiral Nematic Liquid Crystal

“…Microlens arrays are widely used in applications such as digital projectors, imaging and sensor systems, beam homogenizing and shaping, fiber coupling, and light-field microscopy [1][2][3][4][5]. With the increased popularity of 3D imaging, augmented reality and virtual reality devices, a flat microlens array with tunable focusing power is favored for its potential of building compact optical systems, and liquid crystal (LC) is a great candidate for this purpose.…”