Thin-layer spectroelectrochemical cuvette cells with long optical path lengths

1988 ◽  
Vol 60 (15) ◽  
pp. 1645-1648 ◽  
Author(s):  
Yupeng. Gui ◽  
Steven A. Soper ◽  
Theodore. Kuwana
Keyword(s):  
Thin Layer ◽  
Optical Path ◽  
Path Lengths

Quasi-Common-Path Laser Feedback Interferometers for Precision Measurement of Non-Cooperative Targets

2008 ◽  
Vol 381-382 ◽  
pp. 49-52
Author(s):  
X.J. Wan ◽  
Shu Lian Zhang
Keyword(s):  
Optical Path ◽  
Heterodyne Detection ◽  
Reference Mirror ◽  
Phase Fluctuations ◽  
Common Path ◽  
Laser Instability ◽  
Phase Variations ◽  
Path Lengths ◽  
Contact Displacement ◽  
Feedback Light

In this paper, we report a novel quasi-common-path laser feedback interferometer (QLFI) for highly stable, high-resolution and non-contact displacement measurement. QLFI measures the displacement of the target by measuring the phase of feedback light. In addition to the target-generated feedback light (frequency shifted by 2#), a reference mirror generates a reference feedback light which is frequency shifted by #. The phase variations of both feedback lights are measured by heterodyne detection simultaneously and their difference offers the phase variations caused only by target displacement. When the optical path lengths of the reference and measuring feedback light are nearly the same, the phase fluctuations caused by the environment and laser instability are effectively removed. The heat-induced deformation of a He-Ne laser tube is successfully in-line measured using QLFI.

Wavelength-modulated heterodyne grating shearing interferometry for precise displacement measurement

2014 ◽  
Vol 3 (4) ◽  
Author(s):  
Hung-Lin Hsieh ◽  
Ju-Yi Lee ◽  
Yu-Che Chung
Keyword(s):  
Light Beam ◽  
Phase Variation ◽  
Measurement Range ◽  
Optical Path ◽  
Displacement Measurement ◽  
Measurement Sensitivity ◽  
Double Refraction ◽  
Shearing Interferometry ◽  
Birefringent Crystal ◽  
Path Lengths

AbstractA wavelength-modulated heterodyne grating shearing interferometry using a birefringent crystal is proposed for two-dimensional displacement measurement. There is a difference in the optical path lengths of the p- and s- polarizations of the light beam in the birefringent crystal because of the double refraction caused by the birefringence. By passing through the unequal-path-length optical configuration, the wavelength-modulated light beam is converted into a heterodyne light beam having two frequencies. The modulated heterodyne light beam is further combined with grating-shearing interferometry based on the quasi-common-optical-path (QCOP) design concept. According to the working principle and the Jones calculation, the displacement information of a moving grating can be obtained by means of the optical phase variation resulting from the grating. Theoretical analysis shows that the measurement sensitivity of the proposed method is about 0.134°/nm. The experimental results indicate that the resolution is about 10 nm for the centimetric-level measurement range.

2D integrating cell waveguide platform employing ultra-long optical path lengths

2017 ◽  
Author(s):  
Lena Simone Fohrmann ◽  
Gerrit Sommer ◽  
Giampaolo Pitruzzello ◽  
Thomas F. Krauss ◽  
Alexander Yu. Petrov ◽  
...  
Keyword(s):  
Optical Path ◽  
Path Lengths
Sign in / Sign up

Export Citation Format

Share Document