Multispectral molded optics transparent in the visible and in thermal infrared – OMVIR

The work program with the leading team is the following:
The task 1 is dedicated to project management

Task 2 : Development of glasses transparent from visible to 12µm ( LVC )
The objective of this task is to develop glasses transparent from visible up to 12 microns , for simultaneously imaging in the visible / SWIR and thermal infrared region of 8-12 microns with the same optical system. This task is divided into three sub-tasks

Task 3: Precision molding of multispectral optics ( LVC )
The objective of this task is to demonstrate the feasibility of multi- spectral optics by molding of glasses developed in Task 2 .

Task 4: Design and deposition of anti-reflective coatings (THALES )
This task is to develop a broadband antireflection coating for optics with an average transmission greater than 97% in both specified spectral bands.

Task 5: Case study of employment, performance evaluation and proposal for future development ( THALES )
Two optical systems merging visible images / thermal infrared images or near infrared images (0.7 to 1.7 microns ) / thermal infrared images will be designed and their performance will be evaluated. One commercial application and one defense applications will be proposed.

We are in the first year of this project. The specification of needs was established by THALES-ANGENIEUX. The Ga2S3-GeS2-CsCl glass-forming system has been studied in detail. Two compositions were selected for complete characterization (optical transmission, chemical durability, refractive index, chromatic dispersion, change in refractive index as a function of temperature, density, resistance to crystallization ...)

In case of success, this project will improve the position of Thales Angénieux in the field of security and surveillance: more compact multispectral systems with a unique entry will be able to be offered. TAGX shows the ambition of doubling its business in this market in five years.

An oral presentation in a well recognized international conference :
New solutions and technologies for uncooled infrared imaging,
Joël Rollin, Frédéric Diaz, Christophe Fontaine, Thales Angénieux S.A. (France);
Brigitte Loiseaux, Mane -Si Laure Lee, Christophe Clienti, Thales Research and
Technology (France); Xianghua Zhang, Laurent Calvez
2013 Defense, Security, and Sensing, April 29 – May 3 2013, Baltimore USA

The objective of this project is to develop multispectral molded optics operating simultaneously in the visible/short wave infrared (SWIR) and far infrared between 8-12 µm. These optics will allow the fusion of images taken in these two complementary spectral bands with the same optic, leading to a simplification of design and fabrication as well as important decrease of cost and weight.
Imaging in visible/SWIR and in far infrared has many applications still in rapid growth. The fusion of the two complementary images will lead to many new applications both in commercial and defense fields. As an example, for car driving assistance, visible/SWIR image is better for reading road indications and for detecting the presence of ice on the road. Thermal image is much better for seeing further and pedestrians in foggy condition and during the night. For defense applications, it is, for example, easier to move in the dark with intensified SWIR image and thermal imaging is indispensible to detect hidden hot target.
There are many optics operating either in the visible/SWIR region or in the far infrared region. Only two materials, known since long time, ZnS and ZnSe, can be considered for producing multispectral optics even they cover only partially these two spectral bands. These materials are fabricated with the long and expensive chemical vapor deposition (CVD). They are polycrystalline materials and consequently, no molded optic is possible. The only way to produce complex asphero-diffractive optics, indispensable with these materials, is to use the expensive single point diamond tuning.
In this project, we propose to
- develop some new glasses transparent from visible to far infrared up to 12 µm.
- develop a molding process for fabricating multispectral optics
- develop large band antireflection coating
- study some potential applications with the multispectral optics. One commercial application and one defense application will be proposed.
The originality and novelty of this project are associated with the following
- Completely new glasses transparent from visible to far infrared will be developed. The base compositions are protected by a CNRS patent which has been extended to most industrialized countries.
- The first molded multispectral optic will be developed
- A system with fused visible/SWIR image and thermal image will be proposed with the same entrance optic, leading to simplified design and fabrication. This should be considered as breaking technological innovation.
This consortium is composed of an academic laboratory and an industrial partner well recognized in their field of expertises, with a long term relationship of successful cooperations. These cooperations have, for example, allowed the industrialization of molded infrared optics which are installed in the BMW cars for driving assistance and also in the infrared cameras of the World most important manufacturer.