optoelectronics device

optoelectronics device

• 2.
  OPTOELECTRONICS ➢ Optoelectronics isthe study and application of electronic and devices that interact with light.
• 3.
  ❖ Those electronicsdevices which source , detect and control light. ➢ Emitters: convert electricity into light. ➢ Photomessive ( non-solid state) & photoreactors ( solid state devices) convert light into electricity.
• 4.
  ➢ Semiconductor diodethat emits incoherent narrow spectrum light when electricity is passed. ➢ Forward bised P-N junction
• 5.
  P N ➢ Forwardbiased P-N junction and which emits visible light. ➢ charge carrier recombine and takes place when electron form N- side cross the junction and recombine with the holes on P- side. ➢ Electrons are in higher conduction band in N-side ➢ Some of the energy difference in form of photons ( energy packets) or heat is formed. ➢ LED emits no light when in reversed biased.
• 6.
  ➢ P typelayer is kept uppermost ➢ N types is grown on substrate ➢ The metal anode connection are at the outer edge of the P-edge ➢ In order to avoid reabsorption process, LED are made of domed lenses ➢ A metal film is applied for reflecting light as much as possible and also protect cathod and wires ➢ Charge Carrier Recombine and LED work as light emitting Diodes
• 7.
  ❖ Burglar AlarmSystem ❖ CRT ❖ image sensing circuit in phone
• 8.
  ❖ Silica fiberoptical cables ❖ Seven segment Array of Color in LEDs
• 10.
  PHOTOMULTIPLIER TUBE
• 11.
  WHAT IS IT? •Extremely sensitive detector of light in the ultraviolet, visible and near infrared • Multiplies the signal produced by incident light by as much as 108 • single photons can be resolved • High gain, low noise, high frequency response, and large area of collection • A tiny and normally undetectable current becomes a much larger and easily measurable current
• 12.
  COMPONENTS • Made ofa glass vacuum tube • Photocathode • Several dynodes • One anode
• 13.
  HOW IT WORKS
• 14.
  HOW IT WORKS ◼Electron is released by the photocathode ◼ Electron is then multiplied by the electrodes ❑ Metal channel dynodes ◼ At the end of the chain is the collection electrode ❑ Anode ◼ The current flowing from the anode to ground is directly proportional to the photoelectron flux generated by the photocathode