Optical properties of plastic materials for medical vision applications

Abstract

Abstract. Several types of optical polymer materials suitable for ophthalmic or medical vision applications have been studied. We have measured refractive indices of studied plastics at various wavelengths in the visible and near-infrared spectral regions. Important optical characteristics as Abbe numbers, dispersion coefficients and curves, principal and relative partial dispersion have been evaluated. Calculated refractometric data at many laser emission wavelengths used for medical surgery, therapy and diagnostics is included. As an example of a medical vision application of plastics, optical design of a micro-triplet for use in disposable endoscopes is presented. IntroductionThe variety of medical applications of optical plastic materials expands in consumer optics as well as in high precision vision devices. Over 50 percent of all eyeglass lenses sold nowadays are made of organic polymers. Except in ophthalmology, many surgical and diagnostic instruments as laparoscopes, arthroscopes, cystoscopes, endoscopes, etc. apply plastic materials [1]. The use of polymer optics is found in a wide range of not only clinical vision applications such as digital cameras, fiber photonic elements and systems, microscopes, surgical head-mounted video displays, LCD projectors, videoconferencing devices and mobile imaging. The rapid development of microelectronics and semiconductor industries places high demands on the performance of the applied miniature optical elements. Improvements in polymer and integrated hybrid glass-polymer components and systems offer efficient and compact solutions to meet these demands [2].Optical polymers (OPs) have several key advantages over glasses as reduced weight and cost, high impact and shatter resistance and ability to integrate proper mechanical and optical features [1]. The injection-moulding process is very effective to reproduce not only spherical but sophisticated optical shapes such as aspheres, and other complex geometric surfaces or elements with noncircular apertures. Obviously, unique priority of polymers in medical applications is safety. The major drawbacks of plastic materials are that they have less scratch resistance and are more sensitive to environment changes such as temperature and humidity. Plastics lenses can be supplied with hard, anti-abrasion coatings with anti-static and hydrophobic properties, helping to maintain the transparency of the surfaces and making them easier to clean [3]. Broad thermal range functionality and better correction of aberrations of medical vision components and devices can be achieved by usage of hybrid glasspolymer optics. Incorporation of plastics and glass may result in low-cost, high-performance and high-

Evaluation of high temperature polymers in nanolayered films and gradient refractive index (GRIN) lenses

“…Optical grade polymers have been widely used in many optical products and applications, including charge‐coupled device (CCD) cameras, prisms, laser collimation, sensors, medical disposal optics, and optical fibers . Polymer materials have advantages as compared with traditional inorganic glasses which include lower material density, better impact resistance, and ease of mass producibility/lower cost.…”