Related Experiment Video
Updated: Jun 20, 2026

Low-cost Custom Fabrication and Mode-locked Operation of an All-normal-dispersion Femtosecond Fiber Laser for Multiphoton Microscopy
Published on: November 22, 2019
Single-mode-fiber 1 x N directional coupler
Abstract:
We report the development of an adjustable single-mode-fiber multiterminal directional coupler that exhibits efficient coupling and uniform terminal output over a wide range of coupling coefficients. The device is made using a new technique that employs silicon V-groove substrates in the fabrication of arrays of evanescently coupled taps on single-mode fibers. The coupler is highly directional and polarization independent and exhibits excess loss as low as 0.09 dB per terminal in a 1 x 7 device. The fabrication technique may be extended to produce devices having large numbers of terminals. Applications include use in fiber data-bus systems and as a tapped delay line for broadband signal processing.
Related Concept Videos
Spin–Spin Coupling: Two-Bond Coupling (Geminal Coupling)
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...
Transmission Line Design Considerations
Directional Relays
Spin–Spin Coupling: One-Bond Coupling
Energy Stored In A Coaxial Cable
In the simplest form, a coaxial cable can be represented by two long hollow concentric cylinders in which the current flows in opposite directions. The magnetic field inside and outside the coaxial cable is determined by using Ampère's law. The magnetic field inside...
MOSFET: Enhancement Mode
In their basic form, enhancement-mode MOSFETs are typically non-conductive when the gate-source voltage (Vgs) is zero. This default 'off' state means no current...

