Realization of detector based spectralresponsivity scale from ultraviolet to near infrared regions of electromagnetic spectrum

Download
2004
Bazkır, Özcan
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.

Suggestions

Non-linear optical properties of two dimensional quantum well structures
Ağanoğlu, Ruzin; Tomak, Mehmet; Department of Physics (2006)
In this work optical properties of two dimensional quantum well structures are studied. Variational calculation of the eigenstates in an isolated quantum well structure with and without the external electrical field is presented. At weak fields a quadratic Stark shift is found whose magnitude depends strongly on the finite well depth. It is observed that under external electrical field, the asymmetries due to lack of inversion symmetry leads to higher order nonlinear optical effects such as second order opt...
Series solution of the wave equation in optic fiber
Çıldır, Sema; Çakır, Serhat; Department of Physics (2007)
In this study, the mapped Galerkin method was applied to solve the vector wave equation based on H field and to obtain the propagation constant in x y space. The vector wave equation was solved by the transformation of the infinite x y plane onto a unit square. Two-dimensional Fourier series expansions were used in the solutions. Modal fields and propagation constants of dielectric waveguides were calculated. In the first part of the study, all of the calculations were made in step index fibers. Transvers...
Design and analysis of ultrashort femtosecond laser amplifiers
Doğan, Ersin; Bilikmen, Kadri Sinan; Department of Physics (2006)
This thesis presents a compact femtosecond laser amplifier design for optical preamplifiers and power amplifiers consist of theoretical perspective, simulations to analyze and optimize beam performance. The propagation through optical media is simulated for every optical component such as mirrors and nonlinear crystal separately and suggested realignment of these components required increasing amplifier performance. Finally Gaussian beam propagation and aberration compensation has been conducted.
Enhanced second harmonic generation from coupled asymmetric plasmonic metal nanostructures
Yıldız, Bilge Can; Taşgın, Mehmet Emre; Abak, Musa Kurtuluş; Coskun, Sahin; Ünalan, Hüsnü Emrah; Bek, Alpan (IOP Publishing, 2015-12-01)
We experimentally demonstrate that two coupled metal nanostructures (MNSs), a silver nanowire and bipyramid, can produce similar to 30 times enhanced second harmonic generation compared to the particles alone. We develop a simple theoretical model, presenting the path interference effects in the nonlinear response of coupled MNSs. We show that the reason for such an enhancement can be the occurrence of a Fano resonance due to the coupling of the converter MNS to the long-lived mode of the attached MNS.
Study of the Influence of Transition Metal Atoms on Electronic and Magnetic Properties of Graphyne Nanotubes Using Density Functional Theory
Alaei, Sholeh; Jalili, Seifollah; Erkoç, Şakir (Informa UK Limited, 2015-01-01)
Density functional theory calculations were used to study the adsorption of three transition metal atoms (Fe, Co, and Ni) on the external surface of two zigzag and two armchair graphyne nanotubes. The most stable position for the adsorption of all three metal atoms on all nanotubes is on the acetylenic ring. The metal atom remains in the plane of the acetylenic ring and makes six bonds with neighboring carbon atoms. Fe and Co complexes are magnetic and show different properties such as metal, semimetal, hal...
Citation Formats
Ö. Bazkır, “Realization of detector based spectralresponsivity scale from ultraviolet to near infrared regions of electromagnetic spectrum,” Ph.D. - Doctoral Program, Middle East Technical University, 2004.