Optoelectronics is the study and application
of electronic devices that source, detect and control light,
usually considered a sub-field of photonics
Light often includes invisible forms of radiation such
as gamma rays, X- rays, ultraviolet and infrared, in
addition to visible light. Optoelectronic devices are
electrical-to-optical or optical-to-electrical transducers, or
instruments that use such devices in their operation.
Why Is Optoelectronics Important?
Compared to copper wire, optical fibers cost less,
weigh less, have less attenuation and dispersion and
provide more bandwith.
Highly used in electronic
Forward biased junction
Current flows from n side to the p side
Band Gap or Energy Gap (EG): Difference of energy
between the conduction band and valance band
Wavelength of emitted light depends on EG
Most widely used material for visible spectrum: GaAs,
GaP, and GaAsP
A laser is a device that emits light through a process
of optical amplification based on the stimulated
emission of electromagnetic radiation
an NPN bipolar
transistor with an
exposed base region. Here,
the base replaces what
would ordinarily be voltage
applied to the base.
Time-Division Multiplexing (TDM)
E.g. Telephone lines
E.g. FM radio
Compact Disc Players
Infrared Remote Control Devices
Astronomy, Spectroscopy, Night Vision
Equipment And Laser Range Finding.