A stellar ranging scheme based on the second-order correlation measurement

2021 ◽  
Author(s):  
Jian Li ◽  
Can Xu ◽  
Yinshen Liu ◽  
Yaqi Ma ◽  
Xinyao Liu ◽  
...  
Keyword(s):  
Stellar Dynamics ◽  
Optical Path Difference ◽  
Path Difference ◽  
Angle Measurement ◽  
Second Order ◽  
Base Stations ◽  
Baseline Length ◽  
High Precision Measurement ◽  
Correlation Curve ◽  
Geometric Relation

Abstract The stellar ranging is the basis for stellar dynamics research and in-depth research on astrophysics. Parallax method is the most widely used and important basic method for stellar ranging. However, it needs to perform high-precision measurement of the parallax angle and the baseline length together. We aim to propose a new stellar ranging scheme based on second-order correlation that does not require a parallax angle measurement. We hope our solution to be as basic as the parallax method. We propose a new stellar ranging scheme by using the offset of second-order correlation curve signals. The optical path difference between the stars and different base stations is determined by the offset of the second-order correlation curve signals. Then the distance of the stars could be determined by the geometric relation. With the distance to stars out to 10kpc away, our astrometric precision can be better compared to Gaia by simulation. We also design a experiment and successfully prove the feasibility of this scheme. This stellar ranging scheme makes it possible to make further and more accurate stellar ranging without using any prior information and angle measurement.

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

Optical T-Bench Method for Measurement of Optical Path Difference

1963 ◽  
Vol 1 (6) ◽  
Author(s):  
Francis E. Washer ◽  
Walter R. Darling
Keyword(s):  
Optical Path Difference ◽  
Path Difference ◽  
Optical Path

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.

Thermal optical path difference analysis of off-axis lens ray trace foot-print at Cassegrain telescope correct lens assembly

2012 ◽  
Author(s):  
Ming-Ying Hsu ◽  
Yu-Chuan Lin ◽  
Chia-Yen Chan ◽  
Wei-Cheng Lin ◽  
Shenq-Tsong Chan ◽  
...  
Keyword(s):  
Optical Path Difference ◽  
Path Difference ◽  
Optical Path ◽  
Difference Analysis ◽  
Lens Assembly ◽  
Ray Trace ◽  
Cassegrain Telescope

scholarly journals Determination of the refractive index profile and surface topography of optically smooth objects using interference of optical vortices

2021 ◽  
Vol 2103 (1) ◽  
pp. 012166
Author(s):  
B V Sokolenko ◽  
N V Shostka ◽  
D A Poletaev
Keyword(s):  
Refractive Index Profile ◽  
Optical Path Difference ◽  
Path Difference ◽  
Reference Plane ◽  
Optical Vortices ◽  
Vortex Beams ◽  
Singly Charged ◽  
Longitudinal Resolution ◽  
Smooth Objects

Abstract In this paper, we present the results of the propagational dynamics of vortex beams in the scope of their possible applications for interferometric non-contact robust and precision optical surface profilometry with nanoscale longitudinal resolution. The result of coaxial superposition of the reference plane wave with singly charged vortex beams represents a dynamically changing intensity distribution. The nature of this changes, namely, rotational effects of intensity zeros, allows to determine directly the optical path difference which is introduced by the surfaces and internal structure of test object. We have proposed the experimental setup for examination of reflecting and transmitting objects.

scholarly journals Real-time optical path difference compensation at the Plateau de Calern I2T interferometer

2001 ◽  
Vol 365 (2) ◽  
pp. 301-313 ◽  
Author(s):  
B. Sorrente ◽  
F. Cassaing ◽  
G. Rousset ◽  
S. RobbeDubois ◽  
Y. Rabbia
Keyword(s):  
Real Time ◽  
Optical Path Difference ◽  
Path Difference ◽  
Optical Path
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