Large field-induced refractive-index change on TM-polarized light in an InGaAlAs-InAlAs MQW waveguide structure

1997 ◽  
Vol 9 (2) ◽  
pp. 200-202 ◽  
Author(s):  
N. Yoshimoto ◽  
T. Yamanaka ◽  
S. Kondo ◽  
Y. Noguchi ◽  
K. Wakita
Keyword(s):  
Refractive Index ◽  
Refractive Index Change ◽  
Polarized Light ◽  
Waveguide Structure ◽  
Large Field ◽  
Index Change

Nonlinear Susceptibilities in a Three-Level Atomic System

1997 ◽  
Vol 06 (03) ◽  
pp. 333-347
Author(s):  
Nadeem A. Ansari ◽  
Rowland A. Sammut
Keyword(s):  
Refractive Index ◽  
Steady State ◽  
Atomic System ◽  
Refractive Index Change ◽  
Field Experiences ◽  
The Other ◽  
Nonlinear Susceptibility ◽  
Large Field ◽  
Index Change ◽  
Strong Fields

We have studied the effect of the propagation of two strong fields of different frequencies on the nonlinear susceptibility in a medium composed of identical stationary three-level atoms in V-configuration. In particular, we show that each field influences the steady-state susceptibility, absorption and refractive-index change experienced by the other field. At large field strengths of one field, the second field experiences less absorption and an enhanced refractive index change.

scholarly journals Critical angle reflection imaging for quantification of molecular interactions on glass surface

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guangzhong Ma ◽  
Runli Liang ◽  
Zijian Wan ◽  
Shaopeng Wang
Keyword(s):  
Refractive Index ◽  
Small Molecule ◽  
Molecular Interactions ◽  
Glass Surface ◽  
Critical Angle ◽  
Dynamic Range ◽  
Refractive Index Change ◽  
Label Free ◽  
Index Change ◽  
Sensing Range

AbstractQuantification of molecular interactions on a surface is typically achieved via label-free techniques such as surface plasmon resonance (SPR). The sensitivity of SPR originates from the characteristic that the SPR angle is sensitive to the surface refractive index change. Analogously, in another interfacial optical phenomenon, total internal reflection, the critical angle is also refractive index dependent. Therefore, surface refractive index change can also be quantified by measuring the reflectivity near the critical angle. Based on this concept, we develop a method called critical angle reflection (CAR) imaging to quantify molecular interactions on glass surface. CAR imaging can be performed on SPR imaging setups. Through a side-by-side comparison, we show that CAR is capable of most molecular interaction measurements that SPR performs, including proteins, nucleic acids and cell-based detections. In addition, we show that CAR can detect small molecule bindings and intracellular signals beyond SPR sensing range. CAR exhibits several distinct characteristics, including tunable sensitivity and dynamic range, deeper vertical sensing range, fluorescence compatibility, broader wavelength and polarization of light selection, and glass surface chemistry. We anticipate CAR can expand SPR′s capability in small molecule detection, whole cell-based detection, simultaneous fluorescence imaging, and broader conjugation chemistry.

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