Antireflection (AR) properties are required for optical surfaces to avoid disturbing reflections as well as to improve the transmission of optical systems. The common method to reduce the reflection on optics is vacuum deposition of interference coatings. However, special efforts are required for each type of plastic to develop polymer-capable vacuum coating processes due to the manifold chemical and physical properties of optical polymers. An alternative procedure for the antireflection of polymers is the generation of surface structures that decrease the index of refraction in a surface region. In this paper, the suitability of the miscellaneous thermoplastic polymers for plasma-ion assisted deposition processes is evaluated. This comprises the study of damage effects caused by the contact with plasma and high-energy radiation as well as the development of special coating designs and of suitable process conditions. Coating properties achieved are discussed for PMMA and poly-cycloolefines. The same ion source arrangement as used for coating has been applied for etching an antireflective sub-wavelength surface structure into PMMA. In summary, the paper shows the practical application fields for both technologies.
Optical transparent polymers are used for technical optics for more than 50 years and currently replace glass as optical material in several application fields. Optical functional coatings like mirrors, filters, beam splitters and anti-reflection coatings gain increasingly in importance. New light sources and head mounted systems need light and effective reflector designs. The paper gives an overview about vacuum coating technologies for metal and dielectric layers on polymers for technical optics. Especially for polymers controlling the complete process chain from injection moulding to storing, coating and shipping decides on the technological and commercial success.
Zeon Corporation developed quite new optical plastic Cyclo Olefin Polymer; COP(ZEONEX) with own technology in 1990 then started sales for ZEONEX for optical application with its very unique properties such as low birefringence, low water absorption, high glass-transition temperature 136 °C and high light transmission etc. Currently, ZEONEX is well known in optical market and used widely as optical plastic for pick up lens and other many kinds of optical parts for laser beam printer and digital camera. Addition to those ZEONEX grades, in last year, Zeon Corporation developed a new ZEONEX grade called ZEONEX340R, which was designed for blue laser devices requiring more severe specification. ZEONEX340R has high transmission at 405nm which is used laser wavelength for Blu-ray Disk / HD-DVD as well as enough durability under exposure of 405nm laser, addition to those new properties, keeps other optical properties such as low birefringence and very low water absorption.
Glassy liquid crystals (GLCs) possessing multi-functionalities, excellent morphological stability, and elevated phase transition temperature have been designed and synthesized for photonic device applications. Recent development has been reported on deterministic synthesis approach for scalable process in preparing GLC materials. The advanced processing eases the material preparation and tailors the material properties accordingly to suit device applications. These applications can be found in: (1) chiral nematic GLCs for circularly polarizers and notch filters, (2) photochromic nematic GLC, which can be photomodulated reflective indices in the solid states, for potential applications in nondestructive rewritable optical data storages and photonic switching, and (3) ferroelectric GLCs for potential fast switching light valves.
We present a technique for measuring decenter on small-aperture injection-molded optics that combines a simple microscope measurement with basic geometric calculations. A system model comprising both the microscope and the test lens is used to define specific correction factors for calibration. The technique results in repeatable centration measurement accuracy under 3 um, and the direction of the individual surface shifts is also obtained. The level of accuracy achieved has been quantified by comparing point-spread-function measurements and simulations on VGA-quality singlets.
Compact Camera Module (CCM) is widely used in PDAs, Cellular phones and PC web cameras. Nowadays CCM image quality level should match with photo-quality in that frame, optics plays an important role. Among the whole set of optical parameters, flare is particularly threatening as it can waste the world-best-design associated to the world-best-manufacturing-process optics resulting to a simple piece of plastic without any value. Because it acts at the border between optical designer and mechanical designer fields, it is a challenging parameter to study. In this paper, after defining Flare parameter, we show a powerful method for tracking Flare among a complete CCM, through the use of the sensor's emitted intensity diagram. Following this procedure will prevent from random time consuming calculations on flare topic.
Optical interferometry is being used more and more to solve metrology problems. It is important in giving an insight into the properties of the top surface whether it is a processed surface or a thin film coating This paper will discuss metrology issues and ways in which to solve them using autocorrelation. Autocorrelation now commonly used to extract spatial information from surface profiles. It is suitable for looking at processing issues and identifying any periodic errors. An example showing the use of autocorrelation to solve process issues in diamond turning is shown.
Micro-optical devices are very important in current high-tech consumer items. The development of future products depends on both the evolution of fabrication techniques and on the development of new low cost mass production methods. Polymers offer ease of fabrication and low cost and are therefore excellent materials for the development of micro-optical devices. Polymer optical devices include passive optical elements, such as microlens arrays and waveguides, as well as active devices such as polymer based lasers. One of the most important areas of micro-optics is that of microlens design, manufacture and testing. The wide diversity of fabrication methods used for the production of these elements indicates their importance. One of these fabrication techniques is photo-embossing. The use of the photo-embossing technique and a photopolymer holographic recording material will be examined in this paper. A discussion of current attempts to model the fabrication process and a review of the experimental method will be given.
We present a polymer lab-on-a-chip (LOC) microsystem with integrated optics, fabricated by thermal nanoimprint lithography (NIL) in a cyclic olefin copolymer, Topas from Ticona. The LOC contains microfluidic channels and mixers, an absorbance cell, optical waveguides, a microfluidic dye laser, and Fresnel lenses to couple light in and out of the waveguides. The polymer structure is embedded between two glass substrates. By this device we exploit the excellent chemical, mechanical and optical properties of Topas, and demonstrate the fabrication of millimeter to micrometer sized structures in one lithographic step. In addition, the NIL approach allows for addition of nanometer-scale features, limited only by the stamp fabrication. The silicon stamp for the imprint process is fabricated by standard UV-lithography and silicon deep reactive ion etching (DRIE). The sidewall roughness of the DRIE process is reduced to below 15 nm by thermal oxidation and subsequent oxide etching. Prior to imprint the stamp is coated with an anti-sticking coating from a perfluorodecyltrichlorosilane precursor by molecular vapor deposition. Topas, in our case grade 8007, dissolved in toluene is spin coated onto a SiO2 substrate. The imprint temperature is 200 °C, at an imprint force of 15000 N on a 4 inch wafer, imprint time is 5 min. Finally the imprinted structure is bonded to a pyrex wafer with a second layer of Topas in our case grade 9506. Bonding temperature is 70 °C, at a bonding force of 5000 N on a 4 inch wafer. Bonding time is 5 min.
Compact Camera Module (CCM) is widely used in PDA, Cellular phones and PC web cameras. In this paper, a complete list of specifications of optical parameters have been set up from a CCM End User standpoint. Optical parameters are classified into four main sections: first order parameters, image quality parameters, opto-mechanical parameters and environmental parameters. In each section, parameter is defined in parallel with sensor characteristics and final application requirements as well as tailored specificities. Additionally, we have defined parameters for flare discrimination and IR cut-off filter for which we have set up the matching levels of acceptance.
Recently, plastic lenses produced by injection molding are widely used in image taking objectives for digital cameras, camcorders, and mobile phone cameras, because of their suitability for volume production and ease of obtaining an advantage of aspherical surfaces. For digital camera and camcorder objectives, it is desirable that there is no image point variation with the temperature change in spite of employing several plastic lenses. At the same time, due to the shrinking pixel size of solid-state image sensor, there is now a requirement to assemble lenses with high accuracy. In order to satisfy these requirements, we have developed 16 times compact zoom objective for camcorder and 3 times class folded zoom objectives for digital camera, incorporating cemented plastic doublet consisting of a positive lens and a negative lens. Over the last few years, production volumes of camera-equipped mobile phones have increased substantially. Therefore, for mobile phone cameras, the consideration of productivity is more important than ever. For this application, we have developed a 1.3-mega pixels compact camera module with macro function utilizing the advantage of a plastic lens that can be given mechanically functional shape to outer flange part. Its objective consists of three plastic lenses and all critical dimensions related to optical performance can be determined by high precise optical elements. Therefore this camera module is manufactured without optical adjustment in automatic assembling line, and achieves both high productivity and high performance. Reported here are the constructions and the technical topics of image taking objectives described above.
The pressure to "push the polymer envelope" is clear, given the exploding range of demanding applications with optical components. There are two keys to success: 1. Expanded range of polymers with suitable optical properties. 2. Sophisticated manufacturing process options with an overall system perspective: -Tolerances and costs established relative to need (proof-of-concept, prototype, low to high volume production). -Designed to integrate into an assembly that meets all environmental constraints, not just size and weight, which are natural polymer advantages. (Withstanding extreme temperatures and chemical exposure is often critical, as are easy clean-up and general resistance to surface damage.) -Highly repeatable. The thesis of this paper is that systematically innovating processes we already understand on materials we already know can deliver big returns. To illustrate, we introduce HRDT1, High Refraction Diamond Turning, a patent-pending processing option to significantly reduce total costs for high index, high thermal applications.
The rapid and impressive growth of China has been achieved on the back of highly labour intensive industries, often in manufacturing, and at the cost of companies and jobs in Europe and America. Approaches that worked well in the 1990's to reduce production costs in the developed countries are no longer effective when confronted with the low labour costs of China and India. We have looked at contact lenses as a product that has become highly available to consumers here but as an industry that has reduced costs by moving to low labour cost countries. The question to be answered was, "Do we have the skill to still make the product in the UK, and can we make it cheap enough to export to China?" if we do not, then contact lens manufacture will move to China sooner or later.
The challenge to enter the markets of the BRIC (Brazil, Russia, India and China) countries is extremely exciting as here is the new money, high growth and here is a product that sells to those with disposable incomes. To succeed we knew we had to be radical in our approach; the radical step was very simple: to devise a process in which each step added value to the customer and not cost to the product. The presentation examines the processes used by the major producers and how, by applying good manufacturing practice sound scientific principles to them, the opportunity to design a new low cost patented process was identified.