Optics Laboratories

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The Optics Laboratories consists of four units; Detector Radiometry, Photometry, Spectrophotometry and Fiber Optic laboratories. In addition to scientific metrology research activities, within the scope of a government funded project granted in 2012, the Optics Laboratories have started work to establish facilities to test solar panels used to transform solar energy, a significant renewable energy resource, into electrical energy. The aim is to establish a performance test center for silicon and thin film photovoltaic panels that meets the requirements of IEC 61646 and IEC 61215.

The research and development activites performed by the Optics Laboratories can be summarized as follows:


In the Optics Laboratories, measurements of optical energy (J) at 1064 nm, spectral optical power (W), spectral responsivity (A/W), and irradiance (W/m2 . nm) at 250 nm - 2500 nm are carried out. The traceability of optical energy measurements is provided through energy meters calibrated abroad at a metrology institute with higher level standards.

The traceability of the remaining radiometric measurements is obtained from the Cryogenic Radiometer, the primary absolute optical power measurement equipment, available in the Detector Radiometry Laboratory.

Optical energy measurements of pulsed lasers is performed in the range of 10 mJ - 150 mJ at 1064 nm for beam diameters varying from 6 mm to 8 mm. Spectral continuous wave  optical power is measured between 10 µW - 1 W at He-Ne, Ar+ and Nd:YAG discreet wavelentghs and monochromatic radiation wavelengths in the spectral range of 250 nm - 2500 nm.

In these measurements Si, Ge, InGaAs, and pyroelectric radiometers are used as transfer and working standards. With these standards, the spectral responsivity calibrations of the semiconductor and the thermal detectors, sensitive to the same spectral range, are done in the range of 1x10-4 A/W - 1,5 A/W.

The spectral irradiance measurements are performed on the irradiance scale of 1x10-4 W/m2 – 1.4 W/m2 in the same spectral range as the spectral continuous wave (CW) optical power of 250 nm - 1100 nm.  


In the Photometry Laboratory, the luminous intensity unit Candela (cd), which is one of the seven fundamental SI units, and other photometric units; total luminous flux (lm), illuminance (lx), luminance (cd/m2), luminous exposure (lx.s), luminous intensity coefficient (cd/lx) and retro reflection coefficient (cd/(lx·m2), which are derived from the candela, are realized and measured.

The traceability of total luminous flux (lm) is maintained through reference luminous flux lamps calibrated abroad, wheras the traceability of the rest of photometric units is maintained with the cryogenic radiometer .

Luminous intensity (cd), illuminance (lx), luminous exposure (lx.s) and luminance (cd/m2) calibrations are performed in the range of 1 cd - 10000 cd, 0.1 lux - 5000 lx, 10 lx.s - 4000 lx.s, and 1 cd/ m2 - 5000 cd/m2, respectively, with photometers and photometric measurement equipment.

Total luminous flux measurements are carried out in the range of 5 lm - 5000 lm by using an integrating sphere, relative to the calibrated total luminous flux lamp. Luminous intensity coefficient and retroreflection coefficient measurements of retro-reflective materials are performed in 2x10-4 cd/lx - 10000 cd/lx by using the retroreflection measurement setup constructed by the Optics Laboratories.


In the Spectrophotometry Laboratory, spectral transmittance, reflectance and absorption properties of solid and liquid materials, calibration of spectrophotometer instruments, measurements of color temperature of light sources and color parameters of solid and liquid materials, calibration of color measurement instruments, and gloss measurements are  the main areas of activities.

Spectral regular and diffuse reflectance/ transmittance properties of samples are determined using a monochromator based setup in the range of 0.1 - 1.0 reflectance units and of 0.001 - 1.0 transmittance units for the spectral range of 250 nm - 1800 nm.

The wavelength verification and absorption calibration of spectrophotometer instruments are performed using reference liquid and solid filters in the spectral range of 240 nm - 900 nm and 0.0 Abs - 3.0 Abs, respectively.

Standard measurement conditions (d:8°, d:0° and 0°:45°) and two standardized observer fields of view (2° ve 10°) are used in calculation and determination of CIE color parameters (XYZ, Yxy ve L*a*b*).

Gloss measurements are carried out at standardized angles of 20°, 60° and 85°. Spectral reflectance, color, and gloss measurements are traceable to higher standards held abroad,  wheras the rest of spectrophotometric measurements are based on the traceability chain of the TÜBİTAK UME radiometric scale.


In the Fiber Optics Laboratory, fiber optic power (W), attenuation (dB), spectral attenuation of fiber cable (dB/km) and distance (m) measurements are performed for single mode optical fibers.

Fiber optic power and attenuation (fiber optic attenuator) measurements for single mode optical fibers are performed the 10 mW - 380 mW at 1310 nm and 1550 nm and 0.00 dB - 15.00 dB ranges, respectively. These measurements are made with a fiber optic sphere radiometer, InGaAs detectors, fiber optic power meters and attenuator instruments, traceable to the TÜBİTAK UME radiometric scale.

Furthermore, spectral attenuation scale calibration of single mode Optical Time Domain Reflectometers (OTDRs) are carried out over the specral range of 1300 nm - 1325 nm ve 1530 nm - 1570 nm by means of Fiber Optic Attenuation Standards, characterized according to IEC60793-1-40. The distance scales of single mode Optical Time Domain Reflectometers (OTDRs) are calibrated using a Recirculating Delay Line artefact, which generates 10 recirculating transitions and was characterized in the TÜBİTAK UME Optics Laboratories.

The OTDR and fiber optic power related calibrations are performed according to IEC 61746 and IEC 61351, respectively.