OPTICAL DETECTORS IN FIBER OPTIC RECEIVERS.

Slides:



Advertisements
Similar presentations
Chapter 9. PN-junction diodes: Applications
Advertisements

Optical sources Lecture 5.
Transmisi Optik Pertemuan 10 Matakuliah: H0122 / Dasar Telekomunikasi Tahun: 2008.
Optoelectronic Devices (brief introduction)
Contents : CONSTRUCTION PRINCIPLE OF OPERATION CHARACTERISTICS ADVANTAGES DISADVANTAGES APPLICATION.
EE 230: Optical Fiber Communication Lecture 11 From the movie Warriors of the Net Detectors.
Photodetector.
1 Chapter 5 Sensors and Detectors A detector is typically the first stage of a communication system. Noise in this stage may have significant effects on.
Low-Noise Trans-impedance Amplifiers (TIAs) for Communication System Jie Zou Faculty Advisor: Dr. Kamran Entesari, Graduate Advisor: Sarmad Musa Department.
Fiber-Optic Communications
1 Detectors RIT Course Number Lecture Single Element Detectors.
Introduction AD620 Instrumentation Amplifier
Introduction to Fiber Optics
Fiber Optic System TOPIC: INTRODUCTION TO:
Fiber Optic Receiver A fiber optic receiver is an electro-optic device that accepts optical signals from an optical fiber and converts them into electrical.
Optical Receiver Lecture 6.
Thyristors and Optical Devices
CUÑADO, Jeaneth T. GEQUINTO, Leah Jane P. MANGARING, Meleria S.
Chapter 6 Photodetectors.
4/11/2006BAE Application of photodiodes A brief overview.
V. Semiconductor Photodetectors (PD)
1 Light Collection  Once light is produced in a scintillator it must collected, transported, and coupled to some device that can convert it into an electrical.
Photon detection Visible or near-visible wavelengths
3/26/2003BAE of 10 Application of photodiodes A brief overview.
Chapter 5 Optical Detector.
Venugopala Rao Dept of CSE SSE, Mukka Electronic Circuits 10CS32.
ECE 340 Lecture 27 P-N diode capacitance
References Hans Kuzmany : Solid State Spectroscopy (Springer) Chap 5 S.M. Sze: Physics of semiconductor devices (Wiley) Chap 13 PHOTODETECTORS Detection.
Series Connection Series Connection Requires more voltage The supply voltage should be the sum of the rated voltage required for LED.
Incident light with an energy of hv>Eg excites an electron and causes it to jump from the valence band to the conduction band, thereby creating an electron-hole.
Chapter 6 Photodetectors.
Chapter 6 Photodetectors
Fiber Optic Communication Lec 13 By Engr.Muhammad Ashraf Bhutta.
References Hans Kuzmany : Solid State Spectroscopy (Springer) Chap 5 S.M. Sze Physics of semiconductor devices (Wiley) Chap 13 PHOTODETECTORS.
Photo Detectors for Fiber Optic Communication
1 Development of Multi-Pixel Photon Counters (1) S.Gomi, T.Nakaya, M.Yokoyama, M.Taguchi, (Kyoto University) T.Nakadaira, K.Yoshimura, (KEK) Oct
Modulators and Semiconductors ERIC MITCHELL. Acousto-Optic Modulators Based on the diffraction of light though means of sound waves travelling though.
1 Stephen SchultzFiber Optics Fall 2005 Semiconductor Optical Detectors.
Title Light Detectors. Characteristics  Sensitivity  Accuracy  Spectral Relative Response(R( ))  Absolute Sensitivity(S( ))  Signal-to-noise ratio.
FIBER OPTIC TRANSMISSION
Photodetectors What is photodetector (PD)? Photodetector properties
Photodetectors. Principle of the p-n junction Photodiode  Schematic diagram of a reverse biased p-n junction photodiode SiO 2 Electrode  net –eN.
Optical Receivers Theory and Operation
Chapter 6 Noise. Noise is a term generally used to refer to any undesired disturbances that mask the received signal in a communication system. Thermal.
Voltage Divider Circuits Input transducers Input transducers are devices that convert a change in physical conditions (for example, temperature) into a.
Unit-3 FUNDAMENTALS OF FIBER OPTIC COMMUNICATION.
UPM, DIAC. Open Course. March EMITTERS AND PDs 8.1 Emitter Basics 8.2 LEDs and Lasers 8.3 PD Basics 8.4 PD Parameters 8.5 Catalogs.
College Name : Shree Swami Atmanand Saraswati Institute Of Technology(SSASIT)(076) Year : 2 nd year(3 rd sem) EC-2015 Subject Name : Electronic Devices.
EXAMPLE 2 – PHOTODIODE A photodiode is a semiconductor device that converts light into current. The current is generated when photons are absorbed in the.
Topic Report Photodetector and CCD
CUÑADO, Jeaneth T. GEQUINTO, Leah Jane P. MANGARING, Meleria S.
Onoprienko N. E-71. LED or light emitting diode - a semiconductor device with a pn junction created by the optical radiation by passing electric current.
Application of photodiodes
It converts light energy into electrical energy.
OptiSystem applications: Photodiode sensitivity modelling
Optical Emitters and Receivers
Electronics & Communication Engineering
PN-junction diodes: Applications
Special-Purpose Diodes
OPTICAL SOURCE : Light Emitting Diodes (LEDs)
Conversion of optical signal into an electric one.
Photo Detectors.
Applications and Circuits
Photodetectors.
V. Semiconductor Photodetectors (PD)
Chapter 6 Noise.
Introduction to Optoelectronics Optical communication (3) Optical components Prof. Katsuaki Sato.
Optical Receivers Theory and Operation
Introduction to Fiber Optics
Optical Receivers 1. Photo Detectors
Presentation transcript:

OPTICAL DETECTORS IN FIBER OPTIC RECEIVERS. Presenter: Julius Munyantwali.

Introduction. A fiber optic receiver is an electro-optic device that accepts optical signals from an optical fiber and converts them into electrical signals. Consists typically of : -Optical detector -Low-noise amplifier -Other circuitry.

Block diagram of fiber optic receiver.

Optical Detectors. These are transducers that convert optical signals into electrical signals. Transducers are devices that convert input energy of one form into output energy of another. An optical detector does so by generating an electrical current proportional to the intensity of the incident optical light.

Optical Detector Requirements. Compatible in size to low-pass optical fibers for efficient coupling and packaging. High sensitivity at the operating wavelength of the source. Low noise contribution. Maintain stable operation in changing environmental conditions.

Semiconductor Photodiodes. Generate current when they absorb photons. The amount of current depends on ; -Wavelength of the light and responsivity of the photodiode -Size of the photodiode active area relative to the fiber core size -Alignment of the fiber and photodiode.

Optical detector materials. Si,GaAs, GaAlAs – 850nm Ge, InP, InGaAs -1300nm and 1550nm. Materials determine the responsivity of the detector which is the ratio of the output photocurrent to the incident optical power. It’s a function of the wavelength and efficiency of the device.

PIN Photodiode. Semiconductor positive-negative structure with an intrinsic region sandwiched between the other two regions. Normally operated by applying a reverse-bias voltage. Dark current can also be produced which is a leakage current that flows when a reverse bias is applied without incident light.

PIN Photodiode.

Response time factors. Thickness of the active area. -Related to the amount of time required for the electrons generated to flow out of the detector active area. Detector RC time constant. -Depends on the capacitance of the photodiode and the resistance of the load.

Schematic of a Photodiode.

Advantage of PIN photodiodes. The output electrical current is linearly proportional to the input optical power making it a highly linear device. Low bias voltage(<4v). Low noise Low dark current High-speed response

AVALANCHE Photodiodes. An APD internally amplifies the photocurrent by an avalanche process when a large reverse-bias voltage is applied across the active region. The gain of the APD can be changed by changing the reverse-bias voltage.

AVALANCHE Photodiode.

Light Emitters As Detectors. LEDs and lasers can also be used as light detectors making them half-duplex fiber optic communication devices. They can be used alternately as light emitters and detectors allowing transmission of information in either direction over the fiber. In order for the LED to operate as a full-duplex, the temperatures at both ends should be carefully chosen.

Ping-Pong(Full-Duplex) LED.

Questions And Comments.