What is waveguide sensor?
Nanophotonic waveguides are at the core of a great variety of optical sensors. These structures confine light along defined paths on photonic chips and provide light–matter interaction via an evanescent field.
How does an optical waveguide work?
An optical waveguide is a spatially inhomogeneous structure for guiding light, i.e. for restricting the spatial region in which light can propagate. Usually, a waveguide contains a region of increased refractive index, compared with the surrounding medium (called cladding).
What does an optical sensor detect?
In general, an optical sensor measures light and its characteristics and produces a representative electronic signal. When the light is affected by external forces, optical sensors can be used as transducers to measure things such as displacement, temperature and even voltage and current.
Which waveguide is widely used in optical fiber?
Circular waveguide (optical fibers). Circular waveguides, commonly referred to as optical fibers, are the most common form of light waveguide used for optical communication.
What are the modes of waveguide?
Waveguide mode stands for a unique distribution of transverse and longitudinal components of the electric and magnetic fields. There are two types of waveguide modes that can propagate in the waveguides: TE (Transverse Electric) and TM (Transverse Magnetic).
Why optical fiber is called wave guide?
Optical fiber is actually a waveguide for light and operates in accordance with a principle known as total internal reflection. Total internal reflection happens when a propagated wave strikes the boundary between two dissimilar materials, provided that the angle of incidence is larger than the critical angle.
How do optical biosensors work?
An optical biosensor is a compact analytical device containing a biorecognition sensing element integrated with an optical transducer system (Figure 1). The basic objective of an optical biosensor is to produce a signal which is proportionate to the concentration of a measured substance (analyte).
Where is optical sensor used?
Optical sensors are integral parts of many common devices, including computers, copy machines (xerox) and light fixtures that turn on automatically in the dark. And some of the common applications include alarm systems, synchros for photographic flashes and systems that can detect the presence of objects.
What is M and N in waveguide?
The numerals M and N are always integers that can take on separate values from 0 or 1 to infinity. These indicate the wave modes within the waveguide. Only a limited number of different m, n modes can be propagated along a waveguide dependent upon the waveguide dimensions and format.
What is ridge waveguide?
A waveguide with conducting ridges protruding into the center of the waveguide from the top wall or bottom wall or both walls, is called as a Ridged Waveguide. The ridges are parallel to the short wall of the waveguide.