Experimental Investigation of the Rapid Fabrication of Micron and Submicron Structures on Polymers Utilizing Ultrasonic Assisted Embossing

Small-scale optical components with micron or submicron features have grown in popularity in recent years. High-quality, high-efficient, and cost-effective processing approaches for polymer optics mass production are an urgent need. In this study, ultrasonic vibration will be introduced in embossing. The major advantage is that the required energy can be provided for process times ranging from a few hundred milliseconds to a few seconds, and that the process energy is provided at exactly the required location so that the structures in the surrounding area are not affected. Due to the strong correlation between electrical impedance and the temperature of the material, a novel impedance-based control strategy has been utilized for precisely controlling ultrasonic vibration during the embossing process. The investigation used two types of stamps with grating line widths of 4 µm and 500 nm, respectively. As a result, an embossing time of less than a few seconds was accomplished and a uniform embossed surface with an average fill rate of more than 75% could be achieved.

Development of Telescopic Glasses Optical System Based on Polymer Lens

Polymeric materials are actively used to upgrade existing optical devices in order to improve their physical and optical properties. High-tech and relatively cheap polymer optics is a means of solving technical problems related to reduction of assembly labor intensity, improvement of design and reliability of various optical systems. Currently, ophthalmology is the most advanced area for polymer technology development. The defining trend of improving spectacle optics is gradual replacement of lenses made of silicate glass with lenses made of polymer materials, the undoubted advantages of which are almost twice lower density and significant impact resistance. This work is devoted to the development of an optical system of telescopic glasses of small multiplicity, made by the scheme Galileo using modern optical polymers. The device is designed to improve the performance of the eye and can be used for medical operations. The calculation of the presented optical system is carried out by the Zemax program. The resulting optical system is characterized by high image quality, light weight and compactness.

Challenges in the Fabrication of Microstructured Polymer Optics

The fabrication of microstructured polymer optics enables a multitude of new options in the design of technical optics. However, challenges arise along the varying process chains of mold insert fabrication, integration into molding tools, replication by means of injection compression molding and metrology. In order to study the effects, diffractive optical elements (DOE) and microlens arrays (MLA) are fabricated using two different process chains. DOEs are fabricated using a laser direct writing (LDW) based mold insert fabrication. The MLA mold insert is produced using ultra-precision milling (UP-milling). Both optical parts are replicated using injection compression molding. The occurring effects are discussed and the results show, that with complete process control high quality microstructured polymer optical parts can be produced and characterized.

Review on Fabrication Technologies for Optical Mold Inserts

Polymer optics have gained increasing importance in recent years. With advancing requirements for the optical components, the fabrication process remains a challenge. In particular, the fabrication of the mold inserts for the replication process is crucial for obtaining high-quality optical components. This review focuses on fabrication technologies for optical mold inserts. Thereby, two main types of technologies can be distinguished: fabrication methods to create mold inserts with optical surface quality and methods to create optical microstructures. Since optical mold inserts usually require outstanding form accuracies and surface qualities, a focus is placed on these factors. This review aims to give an overview of available methods as well as support the selection process when a fabrication technology is needed for a defined application. Furthermore, references are given to detailed descriptions of each technology if a deeper understanding of the processes is required.