Objective:
Major research activities of RRCAT are on design, development and utilization of advanced Light Sources such as Lasers and Synchrotron Radiation Sources. These sources require specialized optical components apart from the conventional optics. The division has facilities for fabrication, refurbishing and polishing of optical components required for various research activities of this center. ODDL has developed techniques for polishing Nd-Glass, Nd-YAG, Nd-YLF laser rods, Nd-Glass amplifier disks and polishing of optical components made from different non-linear and electro-optic crystals such as LiNbO3, KTP, hygroscopic materials such as KDP, KD*P, ADP, BBO etc, metal mirrors such as Copper, Copper-Nickel, Stainless Steel and Molybdenum, glass components for different types of dye laser cells, CaF2 , KCl windows, BK-7 and fused silica optical components such as windows, parallel plates, wedged plates, lenses, prisms (Penta, Corner cube, Dove, Fresnel Rhomb, Right angled), Glass Axicons, and expertise in fabrication of super smooth optical surfaces on BK-7 and Fused silica substrates, Etalons, Cylindrical & Toroidal optical surfaces, etc. Indigenous and home developed machineries and test equipment have been used for fabrication and characterization of optical components. Apart from optical fabrication, ODDL involves in research work related to optical metrology and characterization.
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Fabrication of specialized optical components
Fabrication of Nd: Glass Laser RodsODDL has developed technique for fabrication of Nd: glass laser rods from raw Nd: glass blanks. The fabrication involves number of machining operations such as, sawing/cutting, milling, and rounding. The flat end surfaces of the fabricated rods are grinded and polished to required optical finish and parallelism for end use. Laser rods of maximum 80 mm diameter and 350 mm length can be fabricated.
Nd: Glass laser rod fabrication from Nd: glass slab
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Fabrication of large size Nd: glass discs
(a) Un-polished Nd: glass disc
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(b) polished Nd: glass discs
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Nd: glass slabs are used in disc amplifiers of Nd: glass laser systems. Un-polished raw Nd: glass discs have typical dimensions of 300 mm x 150 mm x 50 mm. Technique for polishing such large Nd: Glass discs surfaces has been developed using conventional grinding and pitch polishing. Required mechanical fixtures and holders were designed and fabricated to achieve a good surface flatness of the order of λ/10 (λ @589.3 nm) over 100 mm diameter. Alternately, double side optical polishing machine is also available. The machine can simultaneously polish 3 numbers of 400 mm diameter flat optics on both their sides.
Fabrication of cylindrical and toroidal optical surfaces
Cylindrical lens fabrication.
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Elastic bending mechanism for fabrication of Toroidal optical component.
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Cylindrical and toroidal optical components are needed in many optical systems especially in synchrotron beam lines. A cylindrical grinding/polishing machine has been developed in-house for generating and polishing of cylindrical surfaces. Both convex and concave cylindrical optics have been fabricated using the machine.
Toroidal optical surfaces have been fabricated by elastic bending a glass strip to the desired radius and grinding it flat in the bent condition. The relatively shorter cylindrical radius is generated and polished on the stressed surface using the cylindrical polishing machine. The toroidal surface is produced after the stress is relieved.
Fabrication of Pyramidal Mirrors for Cold Atom ApplicationsPyramidal mirrors are special type of optical components used in magneto-optical trap (MOT) of laser-cooled atoms. Cold atoms are used for performing basic science experiments and in developing several atom-optic precision measurement devices including atom clock, atom gravimeter, atom gyroscopes, cold atom based UHV sensors and quantum information processing devices, etc. The pyramidal mirror has a vital role in miniaturization of the MOT setup. These mirrors are not easily available in the market. Gold coated Pyramidal Mirrors have been designed and developed in-house at ODDL. The mirror consists of four identical triangular faces, in which the adjacent faces make an angle of 120◦ and the opposite faces make an angle of 90◦ with each other at vertex point.
Pyramidal Mirror
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Fabrication of other optical componentsPyramidal mirrors are special type of optical components used in magneto-optical trap (MOT) of laser-cooled atoms. Cold atoms are used for performing basic science experiments and in developing several atom-optic precision measurement devices including atom clock, atom gravimeter, atom gyroscopes, cold atom based UHV sensors and quantum information processing devices, etc. The pyramidal mirror has a vital role in miniaturization of the MOT setup. These mirrors are not easily available in the market. Gold coated Pyramidal Mirrors have been designed and developed in-house at ODDL. The mirror consists of four identical triangular faces, in which the adjacent faces make an angle of 120◦ and the opposite faces make an angle of 90◦ with each other at vertex point.
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