scholarly journals Determination of Nonlinear Refractive Index of Zinc Phthalocyanine by Pump Induced Fizeau Interferometry

2019 ◽  
Vol 69 (1) ◽  
pp. 27-30
Author(s):  
Anil Kumar ◽  
M. P. Singh ◽  
Devendra Mohan ◽  
A. K. Gupta
Keyword(s):  
Refractive Index ◽  
Optical Path Difference ◽  
Path Difference ◽  
Specific Region ◽  
Optical Path ◽  
Zinc Phthalocyanine ◽  
Fizeau Interferometer ◽  
Linearly Polarized ◽  
Intense Light

Experimental measurement of intense light induced refractive index is demonstrated using Fizeau interferometer. Refractive index is induced in a specific region of the sample with intense light pulse of a linearly polarized, Q- switched Nd:YAG laser at 1064nm wavelength. The respective change in optical path difference (OPD) is measured using Fizeau interferometer. The OPD so obtained is mapped in terms of change in refractive index in the area of interaction of pump beam and sample. The measured induced refractive index is then used to calculate thermo-optic coefficient of the ZnPc embedded polymeric sample.

Thermo-Fluid Design Simulation of Nd3+ POCl3 Transverse Flow Liquid Laser Cavity

2021 ◽  
pp. 1-31
Author(s):  
Vinod Singh ◽  
Gaurav Singhal ◽  
Prabal Talukdar
Keyword(s):  
Refractive Index ◽  
Temperature Gradient ◽  
Flow Rate ◽  
Optical Pumping ◽  
Gain Medium ◽  
Optical Path Difference ◽  
Path Difference ◽  
Transverse Flow ◽  
Optical Path ◽  
Liquid Laser

Abstract CFD based thermal design of a transverse flow optical cavity is carried out for 1 kW Nd3+ POCl3 liquid laser source to investigate temperature and velocity distribution in the optical pumping region of the cavity. Temperature gradient and turbulence both affect the refractive index of the liquid gain medium, which results in optical path difference, divergence and hence, poorer quality of the laser beam. The main purpose of this design is to achieve uniform flow and least temperature gradient in the optical pumping region so that the optical path difference can be minimized and a good beam quality can be achieved. CFD model has been developed for carrying out thermo-fluid simulations for this thermal system and based on these simulations, an optimum geometry of inlet ports along with their position from optical pumping region have been proposed. A user defined function (UDF) is incorporated for the input of spatially varying heat source term in each cell of the optical pumping region of the cavity. Variations in refractive index and optical path difference are estimated from the temperature data using another UDF. Simulation reveals that mass flow rate between 1.5 kg/s to 2.0 kg/s maintains the optical homogeneity of gain medium. Preliminary experiments have been carried out to demonstrate the effect of flow rate on the beam divergence and thereby exhibiting the importance of present simulation work.

Determination of Optical Path Difference of White Light Fibre Interferometer Using Peak Tracking Method

2014 ◽  
Vol 71 (5) ◽  
Author(s):  
Ley Hood Hong ◽  
Asiah Yahaya ◽  
Yusof Munajat
Keyword(s):  
Light Source ◽  
White Light ◽  
Optical Path Difference ◽  
Path Difference ◽  
Optical Path ◽  
White Led ◽  
Tracking Method ◽  
Peak Tracking ◽  
Wavelength Resolution

The aim of this paper is to evaluate the peak tracking method for determination of optical path difference of a fibre interferometer. This study narros the scope for Mach-Zehnder configuration with neutral white LED as its light source. The peak tracking method is then applied on the interference spectrum recorded from the output port of the interferometer using a spectrometer, allowing the optical path difference to be computed. Accuracy of this method is greatly affected by the wavelength resolution of the detector, where the uncertainty of the result is smaller with higher wavelength resolution and the maximum measurable path difference was found to be about 0.6 mm.  

scholarly journals Robust determination of optical path difference: fringe tracking at the Infrared Optical Telescope Array interferometer

2005 ◽  
Vol 44 (25) ◽  
pp. 5173 ◽  
Author(s):  
Ettore Pedretti ◽  
Wesley A. Traub ◽  
John D. Monnier ◽  
Rafael Millan-Gabet ◽  
Nathaniel P. Carleton ◽  
...  
Keyword(s):  
Optical Path Difference ◽  
Path Difference ◽  
Optical Path ◽  
Optical Telescope ◽  
Telescope Array ◽  
Fringe Tracking

scholarly journals Determination of microrelief of the sample by singular beams superposition

2019 ◽  
Vol 43 (5) ◽  
pp. 741-746
Keyword(s):  
Cross Section ◽  
Topological Charge ◽  
Optical Path Difference ◽  
Path Difference ◽  
Optical Path ◽  
Sample Thickness ◽  
Phase Sensitivity ◽  
Rotational Angle ◽  
Time Determination

In present paper we propose easy way to implement method of interfering vortices with opposite topological charge for the real time determination of the thickness and information about the surface of studied samples with the resolution up to 7 nanometers. The determination of the characteristics of the medial cross-section of submicron-objects becomes possible due to phase sensitivity of interfering singular beams to the slightest changes in the optical path difference between them. The dependence of rotational angle of resulting interference pattern in case of different sample thickness for two singular beams superposition is considered in detail.

Peak-to-peak tracking method for measurement of optical path difference: Revisited

Optik ◽  
2015 ◽  
Vol 126 (24) ◽  
pp. 5420-5422
Author(s):  
H.H. Ley ◽  
A. Yahaya ◽  
Y. Munajat
Keyword(s):  
Optical Path Difference ◽  
Path Difference ◽  
Optical Path ◽  
Tracking Method ◽  
Peak Tracking
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