Paras Defence & Space Technologies Limited

Diffractive Gratings

IR Lenses

IR Optics is a precise optic component that can cope with the IR wavelength & is made of special materials used for UV & IR. Our IR Optical Lenses are high-quality spheres for the near, middle, and far infrared ranges (wavelength range from 3 µm to 5 µm & 8 µm to 12 µm) and are diamond-turned optics with excellent properties for a very wide range of applications.

Materials: Germanium/ Silicon/ ZnSe/ MgF2/ CaF2/ Saphire/ ZnS
Shapes: Sphere/ Aspheric/ Plano/ Diffractive
Coatings: UV/ NIR/ SWIR/ MWIR/ LWIR/ Reflective/ Protective

Silicon Carbide Lenses

Our Silicon Lenses are high-quality spheres for the near, middle, and far infrared ranges (wavelength range from 3 µm to 5 µm & 8 µm to 12 µm) and are diamond-turned optics with excellent properties for a very wide range of applications. Paras Defence has the complete infrastructure for the production of Silicon Lenses with Aspheric, Aspheric Diffractive, as well as Spherical profiles, can be made with the utmost accuracy and precision. Materials such as Germanium, Calcium Fluoride, Zinc Sulphide and Zinc Selenide are also produced.

Germanium Lenses

They are ideal for use in Mid-Wave Infrared and Long-Wave Infrared applications, including thermal imaging, spectroscopy, or FLIR. Due to thermal runaway, or the decrease in transmission as temperature increases, Germanium lenses should be used at temperatures below 100 °C. Germanium’s high density (5.33 g/cm3) should be considered when designing for weight-sensitive systems.

Zinc Sulphide Lenses

Paras Defence supplies a range of quality Zinc Sulphide optical components, including Zinc Sulphide lenses. Zinc Sulphide (ZnS) is a widely used IR-transmitting material used for windows, lenses, and other optical components. The material transmits at about 50% between 0.4 -12 μm before dropping off to zero transmission at around 15 μm. Its low absorbance in the IR spectrum makes it suitable for CO2 lasers operating at 10.6 μm. Zinc Sulphide has a pale yellow appearance and a hardness of HK160. Although the material is resistant to thermal shock, it is not recommended for harsh environments. Zinc Selenide is used in the form of optical windows in FLIR (Forward Looking Infrared) systems, as meniscus, spherical, or cylindrical lenses, and as resonator windows in CO2 lasers.

Diameter	10 to 200 mm
Diameter Tolerance	± 0.005
Center Thickness Tolerance	± 0.008
Focal Length Tolerance	± 2%
Surface Quality	40:20
Surface Irregularity	1 Fringe @ 633 nm

Optics Domes

Paras Defence offers an extensive range of domes of standard sizes for visible & IR applications.

Custom domes are available from 50mm to 400mm in diameter.
Domes are AR-coated for improved transmission.
Materials Processed are ZnS, Sapphire, & BK7.

Gyro Blocks

Typical materials used are Zerodur, Astro-Sital Fused Silica, Bk7, Ohara, & Schott.

Hole roughness up to Ra0.3
Surface Finish up to 5 Å
Surface Flatness up to λ/20
Dimension tolerance up to ±2 microns
Dimension range: up to 15mm-150mm

Diffractive Gratings

$Diffractive-Gratings$

Paras Defence is one of the only companies in India that offers gratings for Hyperspectral Imaging that are used to separate light of different wavelengths with high resolution. These gratings are classified on the basis of different parameters, such as blazing angles, single-blazed or multi-blazed, by maintaining the surface roughness (RMS) up to pre < 5nm in parallel. This “super prism” aspect of the diffraction grating leads to its application for measuring atomic spectra in both laboratory instruments and telescopes, as well as for Space & Critical Applications.

Multi-Fold Lenses

Paras Defence is rapidly expanding its solution portfolio for Space Applications. We are the only company in India that makes Multifold lenses for space imaging in nano-satellite.

Zerodour Mirrors

Paras Defence is one of the top companies in India to offer custom-made precision ZERODUR mirrors. Along with mirrors, Paras Defence also offers ZERODUR lenses, typically made up of Astro-Sital Fused Silica, Bk7, Ohara, & Schott material. We have the capability of manufacturing different shapes, such as Plano, Spherical, Aspherical, and Off-Axis Aspherical. Our vast manufacturing infrastructure gives us the ability to produce mirrors of sizes ranging from as low as 50 mm to as high as 1500 mm. With our ultra-precision machines, Paras Defence offers surface accuracy of up to ʎ/50 RMS & ʎ/8 PV for these lenses.

Reflectors & Coating

Paras Defence has a wide range of technical coating and optics-focused capabilities, from customized design to the final product for Space, Industrial and Commercial use.

Metal Mirrors

Paras Defence contributes significantly to India’s astronomy projects by manufacturing & supplying high-precision Metal Mirrors.

Ultra Precision Manufacturing using Diamond Turning

Paras Defence has a wide range of technical coating and optics-focused capabilities, from customized design to the final product for Space, Industrial and Commercial use.

Lens Barrel

Paras defence offers specialized turnkey solutions for complex Optomechanical lens assemblies. Such type of lens assemblies hold optical elements in proper position and maintain position throughout the range of conditions encountered in the working temperature, pressure and vibration environments of the optical systems. The ability to carry out Zernike and FE (Finite Element) analysis on our lens assemblies gives us the edge to offer solutions which are always predictable and in line with what is required by the system design. With our highly qualified design engineers, we can offer assemblies with an accuracy of focal length up to 150mm. These complex lens assemblies are generally used in Defence & Space applications.

Configurations	1 FOV / 2 FOV / 3 FOV & Continuous Zoom
F Nos.	f/0.85, f/1.2, f/1.25, f/1.4, f/1.6….f/5.5
Focus	Motorised
Focal Lengths	up to 150mm
Zooms	Manual / Continuous
Types	Radiometric & Athermalised

Deployable Space Antenna

For Space And other applications

Paras Defence is rapidly expanding its solution portfolio for Space Applications. In a quest to offer world-class niche solutions for Space, Paras has exclusively partnered with Europe’s leader in Space Antennas. We are in the process of setting up India’s first private Space Antenna manufacturing and integration plant.

Together, we currently offer:

Solid Reflector Antennas
Large Deployable Reflector Subsystems
Deployable Sail Subsystems for De-Orbiting
Nanosatellite Equipment (RF, Mechanical, Thermal)
Thermal Hardware (MLI, Radiators, etc.)

CFRP Structures for Space Applications

With CFRP Structures, Paras aims at offering a comprehensive optical/camera assembly for space applications, where Paras is currently offering high-quality optical elements. CFRP solutions can be explored for various applications where the quality, strength and weight requirements are vital. We can offer any component/structure/sub-assembly/assembly made using CFRP.