Yann Guimond

Comparison of performances between GASIR molded optics and existing IR optics

Umicore IR Glass has developed an industrial process to manufacture low cost chalcogenide glasses with well controlled properties. These materials called GASIR 1 and GASIR 2 are transparent in the 3-5 and 8-12 μm atmospheric windows allowing a great range of applications in thermal imaging. A high precision industrial moulding process has been developed and set up allowing to mould GASIR material directly into high quality finished spherical, aspherical and diffractive lenses. This process is especially attractive for medium and high volume applications. Specific antireflection coatings have also been developed offering a maximum transmission of 98% when coated with high efficiency coating. Several optics from 17.5 mm F/1 to 100 mm F/1.25 focal length based on existing germanium optics have been redesigned especially for GASIR 1 and GASIR 2 glasses. The lenses have been manufactured using Umicore’s moulding technology. These chalcogenide moulded optics are used in various applications like imaging, process control, military applications and their performances (modulation transfer function has been measured) are reviewed and compared to the existing solutions made of traditional IR optics.

Low cost uncooled IRFPA and molded IR lenses for enhanced driver vision

Uncooled infrared focal plane arrays are being developed for a wide range of thermal imaging applications. CEA / LETI developments are focused on the improvement of their sensitivity enabling the possibility to reduce the pixel pitch and the decrease of the system cost by using smaller optics. We present the characterization of a 160 x 120 infrared focal plane array with a pixel pitch of 35 μm. The amorphous silicon based technology is using recent process enhancement developed by CEA / LETI and transferred to ULIS. ULIS developed for this device a low cost package. The readout integrated circuit structure is using an advanced skimming function to enhance the pixel signal exploitation. This device is well adapted to high volume infrared imaging applications where spatial resolution (in term of pixel number) is less important than cost. The electro-optical characterization is presented. Besides, A unique and high precision molding technology has been developed by Umicore IR Glass to produce low cost chalcogenide infrared glass lenses with a high performance level. Spherical, aspherical and asphero-diffractive lenses have been manufactured with very accurate surface precision. The performances are comparable to those of an optic made with aspherical germanium. This new glass named GASIR offers an alternative solution to germanium for thermal imaging, especially for medium and high volumes applications. These two key technologies are well adapted to develop infrared driver vision enhancement (DVE) system for commercial application. A European project named ICAR has been setting up to exploit these advantages. An overview of the project will be given.

Moulded infrared optics making night vision for cars within reach

Sustainable mobility is a major public concern, making increased safety one of the major challenges for the car of the future. About half of all serious traffic accidents occur at night, while only a minority of journeys is at night. Reduced visibility is one of the main reasons for these striking statistics and this explains the interest of the automobile industry in Enhanced Night Vision Systems. As an answer to the need for high volume, low cost optics for these applications, Umicore has developed GASIR. This material is transparent in the NEAR and FAR infrared, and is mouldable into high quality finished spherical, aspherical and diffractive lenses. Umicores GASIR moulded lenses are an ideal solution for thermal imaging for cars (Night Vision) and for sensing systems like pedestrian detection, collision avoidance, occupation detection, intelligent airbag systems etc.

Analysis of biological and chemical compounds by remote spectroscopy using IR TeX glass fibers

The TeX glasses are attracting much attention as materials for low loss mid-IR optical fibers and are consequently good candidates for thermal imaging, laser power delivery, and more recently remote sensing. The TeX glass fiber, transmitting in a wide optical window, has a minimum attenuation in the 9-10 micrometers region. Fibers with an attenuation of less than 0.5 dB/m have been repeatly obtained. These fibers are coated with a UV curable or thermal plastic, in order to improve their mechanical properites. The IR remote spectroscopy using TeX fibers is one of the most promising applications. This technology allows to perform in situ, real-time, and on-line analysis of chemical and biological compounds. The study of industrial processes such as fermentations has been performed by this method, based on the use of these IR TeX fibers.

The radiation tolerance of chalcogenide glasses

Chalcogenide glasses are compounded from chalcogen elements, such as sulphur, selenium, and tellurium. These glasses are applied to commercial applications, e.g., night vision, because they transmit infrared in the spectral range of 0.8-16μm. Chalcogenide glasses have greater advantages over germanium (Ge), i.e., their wide spectral range of high transmissivity and their small temperature dependence of the refractive index. We have developed the Compact Infrared Camera (CIRC) with an uncooled infrared array detector (microbolometer) for space applications. The CIRC has been scheduled to launch in 2013 to demonstrate the usability of a microbolometer as a space application. The optics of the CIRC adopts two different kinds of materials for athermal optics. One is germanium, and the other is GASIR1® which is a chalcogenide glass (Ge22As20Se58) developed by Umicore. However, the radiation tolerance of GASIR® has not been investigated in the past. We carried out irradiation tests to investigate the radiation tolerance of GASIR1®. We irradiated GASIR1® with gamma-rays (Co60, 1.17 MeV and 1.33 MeV) up to 3Mrad. We measured the transmissivity and refractive index in the infrared range before and after irradiation. In this paper, we report the results of the irradiation tests of GASIR1®.

A new moldable infrared glass for thermal imaging and low cost sensing

Umicore, known for its activities in the infrared materials and molded optics, this year launches a new infrared glass called GASIR® 3. This material can be molded using Umicores proprietary molding technology and allows serving a wide range of new markets. Examples are a new automotive commercial application and sensing applications with their need for very small optics. Parallel to the materials development, a new coating has been developed by Umicore that allows the use of GASIR® molded optics in extremely harsh environments. The extreme performance of this new type of coating which complies with the toughest military specs will also be described.

Umicore opens new era in IR moulded optics by opening the first high volume facility

Umicore IR Glass has developed an industrial process to manufacture low cost chalcogenide glasses with well controlled properties. These materials called GASIR® 1 and GASIR® 2 are transparent in the 3-5 and 8-12 μm atmospheric windows allowing a great range of applications in thermal imaging. In the past two years, several optics based on Germanium existing optics (60 mm and 100 mm) have been redesigned for GASIR® glass and are now produced as standards in medium volume series. This year Umicore is passing another step in the production of infrared moulded optics by opening the first high volume factory entirely dedicated to GASIR® optics for driving vision enhancement (DVE). This new facility will have a capacity of several tens of thousands of optics per year. In this article, the first results of performance of the corresponding optics will also be presented.

IR molded optics for thermal imaging

Umicore IR Glass is a company specialising in the production of chalcogenide glasses and moulded optics. The standard glass compositions are GASIR1 (Ge22As20Se58) and GASIR2 (Ge20Sb15Se65). These materials are transparent in the 3-5 μm and 8-12 μm bands. An industrial process has been developed to produce these two glasses with well controlled properties. The reproducibility of refractive index is for example better than 1.5 x 10-4 at 10 μm. A unique and high precision moulding technology has been developed to produce low cost chalcogenide glass lenses with high performance levels. Spherical, aspherical and asphero-diffractive lenses are manufactured with very accurate surface precision. The form defect of the moulded surfaces can be less than 0.3 μm with a typical roughness of 10 nm. When depositing an antireflection coating onto the moulded lenses, the reflection losses are reduced, raising the transmission to 98%, compared to 70% for uncoated lenses. A durable coating has also been developed as a protection for exposed lenses. Coated asphero-diffractive GASIR optics, used in infrared cameras give good quality images. The performance is comparable to that of an optical system with aspherical germanium. GASIR offers a cost-effective alternative to germanium for thermal imaging, especially for medium to high volume applications, both commercial and military.

Umicore offers new solutions for high volume production of infrared optical system

During many years high volume commercial applications of infrared optics have been slowed down by several cost factors. The development of focal plan arrays and uncooled detectors has allowed to greatly reduce the cost of infrared detectors. In the meantime, Umicore IR Glass has developed an industrial process to manufacture low cost chalcogenide glasses with well controlled properties. These glasses called GASIR 1 and GASIR 2 are transparent in the NEAR and FAR infrared atmospheric windows and are mouldable into high quality finished spherical, aspherical and diffractive lenses. The moulding process allows high volume production of cost effective infrared optics. After the development of several optics in GASIR for medium volume series, Umicore is opening the first high volume factory entirely dedicated to GASIR optics for driving vision enhancement (DVE). This new facility will have a capacity of several tens of thousands of optics per year.

High-precision IR molded lenses

Umicore IR Glass is a company specialising in the production of chalcogenide glasses and moulded optics. The standard glass compositions are GASIR1 (Ge22As20Se58) and GASIR2 (Ge20Sb15Se65). These materials are transparent in the 3-5 μm and 8-12 μm bands. An industrial process has been developed to produce these two glasses with well controlled properties. The reproducibility of refractive index is for example better than 2.0 x 10-4 at 10 μm. A unique and high precision moulding technology has been developed to produce low cost chalcogenide glass lenses with high performance levels. Spherical, aspherical and asphero-diffractive lenses are manufactured with very accurate surface precision. The form defect of the moulded surfaces can be less than 0.4 μm with a typical roughness of 10 nm. When depositing an antireflection coating onto the moulded lenses, the reflection losses are reduced, raising the transmission to 98%, compared to 70% for uncoated lenses. A durable coating has also been developed as a protection for exposed lenses. Coated asphero-diffractive GASIR optics, used in infrared cameras give good quality images. The performance is comparable to that of an optical system with aspherical germanium. GASIR offers a cost-effective alternative to germanium for thermal imaging, especially for medium to high volume applications, both commercial and military.