Optics & Aluminising Workshop
Optics section is actively involved in the instrumentation activities related to various projects in the institute. The section has various facilities and instruments for aligning, testing and integration of optical system. The details of facilities and instruments installed are as below:
Clean Room Facility: Optics laboratory has a class-10,000 clean room with laminar flow unit. The clean room has a vibration isolated optical table of 12 x 9 x 9 feet dimension. This facility is used for assembly of optics and electronics (CCD camera etc.) related to the instrumentation programs.
Figure1: The class 10,000 clean room facility with vibration free table installed at optics lab, ARIES, Nainital
2. Optical Profiler cum Phase Shift Interferometer:
Size of samples mirror that be accommodated: up to 500 micron
Vertical resolution : 0.1 nm
Measurement repeatability : 0.1 nm Rq
Z imaging range : <1 nm to 5000 micron
Z – Scan speed : > 3 micron/sec at a height
resolution of 0.1 nm.
Purpose: Surface roughness measurement, Shape profiles of optical elements, step height of coatings on mirror, 3D surface profile analysis.
Figure2: Optical profiler set up (left), measurement sample kept at tip-tilt stage (right)
Model: StellarNet Inc.
Wavelength range (nm): 300-1100
Optical resolution: 1nm
A/d resolution: 16 bit
Connector: SMA type
F ratio: F/4
Stray light: <0.1%
Purpose: Fiber fed instrument used in laboratory experiments.
Figure3: Transmission curve of filter measured using spectrometer
Wavelength accuracy for laser head : ±0.1 ppm over life time
Wavelength stability of the laser head : ±0.02 ppm over life time
±0.002 ppm over 1 hour
Fundamental optical resolution : 0.5 wavelength or better
Non linearity error : < ±5 nm
Dead path correction error : < ±0.15 times dead path distance
Purpose: micron level measurements (linear/angular alignments, vibrations etc.) of mechanical and opto-mechanical systems
Acceptance angle < 2 degree
Angle of incidence < 10 degree
Wavelength range: 365 nm- 97 0 nm
Global absolute accuracy: better than 0.6% for reflectivity> 50%; @400-900 nm
Repeatability: better than 0.02% for reflectivity>50%; @400-900 nm
Purpose: Reflectivity measurement of mirrors over visible wavelength range.
Figure 4: Reflectivity measurement of aluminium coated 3.6m mirror using reflectometer