Dedektör tabanlı tayfsal duyarlılık ölçeğinin elektromanyetik tayfının morötesi ile yakın kızılötesi bölgeleri arasında oluşturulması.

Realization of spectral responsivity scale was studied in three stages. Firstly, absolute optical power measurements using Electrical Substitution Cryogenic Radiometer (ESCR) was studied. The absolute measurements were done at discrete laser wavelengths of tunable Ar+ (488 nm and 514.5 nm), Nd:YAG (532 nm) and fixed He-Ne (632.8 nm) laser sources. To increase measurement accuracy the method used for the stabilization of laser beams, transmittance measurements of optical windows, and minimization of scattered beams were discussed. Secondly, realization of absolute responsivity scale between 350- 850 nm ranges was studied. The scale based on reflection type trap detectors consisting of three silicon photodiodes. Various measurement systems were established in order to make optical characterization of trap detectors like non-linearity, surface non-homogeneity, polarization dependency, reflectance, and internal quantum efficiency. The absolute responsivity was linked to the absolute optical power by measuring the current response of trap detectors to the absolute power measured by ESCR system at laser wavelengths. Using models for the trap detector̕s, reflectance and internal quantum efficiency the scale between 350- 850 nm ranges was realized with an uncertainty of 0.05 %. Finally, the spectral responsivity scale in ultraviolet (UV) and near-infrared (NIR) regions was realized using Electrically Calibrated Pyroelectric Radiometer (ECPR). Optically characterizing the spatial non-uniformity of pyroelectric detector and its surface reflectance, the spectral responsivity scale was established with uncertainties ±0.5-1.0 % between 250 nm and 350 nm and ±0.5-1.5 % between 850 and 2500 nm.Ph.D. - Doctoral Progra

Realization of photometric base unit of candela traceable to cryogenic radiometer at UME

At National Metrology Institute of Turkey (UME, Ulusal Metroloji Enstitüsü), luminous intensity unit of candela was realized using detector-based approach and photometric scale was re-established depending on this new realization. Candela was measured on photometric bench using interferometric distance measurement system and filter-radiometer traceable to UME primary level electrical-substitution cryogenic radiometer. Thermally stabilized filter radiometer, which has been designed for spectral irradiance measurements, is consists of trap detector, filter housing and precision aperture. Different measurement techniques were used to fully characterize each parameter of filter-radiometer; like effective aperture area, spectral transmittance of $V(\lambda)$ filter and responsivity of trap detector

Silisyum tabanlı ışık yayınlayan yapıların üretilmesi

TÜBİTAK TBAG01.02.2001ODTÜ Fizik bölümü Katıhal Elektronik Laboratuvarı'nda (KEL) bulunan plazma destekli kimyasal buhar biriktirme düzeneğinde (PECVD), çeşitli tabanlar üzerine a-SiCx:H filmler büyütülerek kızıl altı soğurma (FTIR), görünür bölge optik soğurma ve özdirenç ölçümleriyle hem yasak enerji, hem de yapısal düzen yönünden film büyütme koşullan belirlenmiştir. Arkasından n ve p türü kaplama süreçleri de düzenli bir biçimde ele alınarak başarılmıştır. Son olarak, p-i-n yapılar oluşturularak yayınlanan ışık kaydedilip, dalga boyu dağılımı çıkarılmıştır