Optical Coupling
Optical Coupling - Related Videos
09:35
Attaching Biological Probes to Silica Optical Biosensors Using Silane Coupling Agents
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Cited by 13 •
2012
Biosensors interface with complex, biological environments and perform targeted detection by combining highly sensitive sensors with highly specific probes attached to the sensor via surface modification. Here, we demonstrate the surface functionalization of silica optical sensors with biotin using silane coupling agents to bridge the sensor and the biological environment.
10:59
Use of Label-free Optical Biosensors to Detect Modulation of Potassium Channels by G-protein Coupled Receptors
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Cited by 5 •
2014
Optical biosensor techniques can detect changes in mass near the plasma membrane in living cells and allow one to follow cellular responses in both individual cells and populations of cells. This protocol will describe detection of the modulation of potassium channels by G-protein coupled receptors in intact cells using this approach.
08:31
Three-dimensional Optical-resolution Photoacoustic Microscopy
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Cited by 27 •
2011
Optical-resolution photoacoustic microscopy (OR-PAM) is an emerging technology capable of imaging optical absorption contrasts in vivo with cellular resolution and sensitivity. Here, we provide a visualized instruction on the experimental protocols of OR-PAM, including system configuration, system alignment, typical in vivo experimental procedures, and functional imaging schemes.
08:58
Silicon Nanowires and Optical Stimulation for Investigations of Intra- and Intercellular Electrical Coupling
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Cited by 3 •
2021
This protocol describes the use of silicon nanowires for intracellular optical bio-modulation of cell in a simple and easy to perform method. The technique is highly adaptable to diverse cell types and can be used for in vitro as well as in vivo applications.
01:20
Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
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2024
Two NMR-active nuclei bonded to a central atom can be involved in geminal or two-bond coupling. Geminal coupling is commonly seen between diastereotopic protons in chiral molecules and unsymmetrical alkenes, among others. The central atom need not be NMR-active because its electrons are affected by the electron polarization of the spin-active atoms. However, spin information is transmitted less effectively than in one-bond coupling, and 2J values are usually weaker than 1J values. The energy of...
FAQs
Efficient transfer depends on matching the optical modes and spatial paths of the connected components. A mode describes the light distribution supported by a fiber or waveguide, while the spatial path describes where that light travels. When these features correspond, more optical power enters the receiving component; mismatch reduces the transferred power and can weaken system performance.
Numerical aperture limits the range of light angles that a component can accept or deliver, so it must be compatible with the connected optical path. Lens geometry shapes and redirects the beam toward the receiving component. Together, these factors influence how much light is captured, making them important when connecting fibers, waveguides, lasers, detectors, or free-space systems.
A refractive-index change at an interface can alter how light propagates between components, while interface reflections prevent some optical power from continuing into the next element. These effects reduce the power available for transmission even when the components are positioned together. Managing the interface is therefore part of improving coupling efficiency in photonic and free-space assemblies.
A setup should first establish the intended spatial path between the source and receiving component, then account for alignment and lens geometry. Engineers also compare the components’ numerical apertures and consider refractive-index changes and interface reflections. Reviewing these variables together helps identify causes of low coupled power and supports a more stable connection between the optical elements.
It is important wherever light must move between distinct optical elements, including fiber communications, integrated photonics, laser systems, optical sensors, and free-space arrangements. In these settings, coupling quality affects signal transmission and optical power delivery. Engineers therefore treat coupling as a system-level concern rather than an isolated connection, because losses or mismatch at one interface can influence overall efficiency.
Engineers reduce sensitivity by treating alignment, mode matching, spatial paths, lens geometry, and numerical aperture as linked design variables. The goal is not simply to place components near one another, but to preserve an efficient optical path despite the practical behavior of the assembly. This approach can reduce insertion loss and support more reliable signal transmission in engineered photonic systems.