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:

Specification:

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)

 

3.UV-VIS-NIR spectrometer:

Specification:

Model: StellarNet Inc.

Wavelength range (nm): 300-1100

Optical resolution: 1nm

A/d resolution: 16 bit

Connector: SMA type

NA: 0.22

F ratio: F/4

Stray light: <0.1%

Purpose: Fiber fed instrument used in laboratory experiments.

Figure3: Transmission curve of filter measured using spectrometer

 

4.Laser interferometer:

Specification:

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

 

5.Reflectometer:

Specification:

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

Soft contacts

Purpose: Reflectivity measurement of mirrors over visible wavelength range.

Figure 4: Reflectivity measurement of aluminium coated 3.6m mirror using reflectometer