High‐Precision Printing of Complex Glass Imaging Optics with Precondensed Liquid Silica Resin

Abstract

3D printing of optics has gained significant attention in optical industry, but most of the research has been focused on organic polymers. In spite of recent progress in 3D printing glass, 3D printing of precision glass optics for imaging applications still faces challenges from shrinkage during printing and thermal processing, and from inadequate surface shape and quality to meet the requirements for imaging applications. This paper reports a new liquid silica resin (LSR) with higher curing speed, better mechanical properties, lower sintering temperature, and reduced shrinkage, as well as the printing process for high-precision glass optics for imaging applications. It is demonstrated that the proposed material and printing process can print almost all types of optical surfaces, including flat, spherical, aspherical, freeform, and discontinuous surfaces, with accurate surface shape and high surface quality for imaging applications. It is also demonstrated that the proposed method can print complex optical systems with multiple optical elements, completely removing the time-consuming and error-prone alignment process. Most importantly, the proposed printing method is able to print optical systems with active moving elements, significantly improving system flexibility and functionality. The printing method will enable the much-needed transformational manufacturing of complex freeform glass optics that are currently inaccessible with conventional processes.

Phosphor‐in‐Silica‐Glass: Filling the Gap between Low‐ and High‐Brightness Solid‐State Lightings

“…In addition, it is also possible to reduce the densifying temperature of silica glass to lower than 900 °C by developing precondensed liquid silica resin. [10] We thus believe that silica glass will be a versatile and robust platform for multifunctional composite materials.…”

“…Silica glass with an ultrahigh softening temperature (1650 °C) is an ideal matrix material that can potentially overcome the above drawbacks of low-melting glasses (see Table S1, Supporting Information, for a detailed comparison). Using amorphous silica nanoparticles [9] or siloxane-based polymers [10] as the raw material makes silica glass accessible to a relatively low temperature (800−1300 °C). Yet it still seems impossible for phosphors to survive after a long-time sintering (>3 h) for obtaining phosphor-insilica-glass (PiSG) converters, considering the previous belief that a mild (temperature <800 °C) and/or fast (holding time <30 min) sintering is a prerequisite for suppressing the undesired interfacial reaction.…”

Two‐Photon Polymerization Lithography for Optics and Photonics: Fundamentals, Materials, Technologies, and Applications

“…Micro-optical elements, lenses, photonic crystals, DOEs and their hybrids, circular polarizers, spin-orbital couplers, etc., can all be miniaturized and combined with optical fibers [474] and imaging devices. [508,675] Photonic wire bonding (PWB) is an exact example of a 3D laser polymerization technology transfer to solve on-a-chip integration challenges for micro-lasers couple to waveguides and optical circuits. Inherent 3D capability of laser writing has brought new functionalities for tapering polymerized photonic links to single-mode fibers and control of the propagation phase via exact length in the bond.…”

Characterizing close-focus lenses for microendoscopy

“…Recent activity has focused on expanding 3D-printed lens material beyond the resins typically used. Liquid silica resin (LSR) has recently been introduced and is an exciting option due to the potential for biocompatibility and higher ultraviolet (UV)/blue transmission where other typically used resins may absorb 17 , 18 . However, it is important to note that the 3D printing fidelity of precision glass optics for imaging applications is still limited by its shrinkage and highly controlled surface accuracy during manufacturing.…”

“…Liquid silica resin (LSR) has recently been introduced and is an exciting option due to the potential for biocompatibility and higher ultraviolet (UV)/blue transmission where other typically used resins may absorb. 17,18 However, it is important to note that the 3D printing fidelity of precision glass optics for imaging applications is still limited by its shrinkage and highly controlled surface accuracy during manufacturing. 3D printing allows for the design of monolithic optical systems, simplifying the alignment process of coupling to a fiber bundle or sensor, and an optical stop can be incorporated directly into the lens system.…”