Design, Measurement, and Applications
DATES AND LOCATIONS
May 23 and 24, 2016.
May 22 and 23,2017
October 17 and 18, 2016.
October 16 and 17, 2017.
November 21 and 22, 2016.
November 20 and 21, 2017
ON-SITE TRAINING: Call for more information at 216-849-2512
Registration Contact: 216-849-2512
Optical communication systems have progressed very rapidly from the research labs into commercial applications. They have already established within the transport network as-point-to point links, broadcast distribution, and interconnecting electrical nodes. Currently the progress of this technology is significantly in the diffusion of multi-wavelength extended capacity links with wavelength routing at the nodes and add-drop operations on the high-data information flowing in the optical domain. Future optical communication networks for terabit transmission rates require the use of optical routing to cope with ever increasing capacity demand due to growing internet traffic. They have been advancing to achieve enhanced personal and multimedia communications. Subcarrier optical transmission is expected to yield simple terminal equipment for many kinds of radio communication and broadcasting applications, because it offers wide-band and multicarrier transmission. As optical communication system technologies have improved, an increasing variety of applications have become technically feasible and economically attractive. The objective of this course is to provide a comprehensive overview of communication systems in the form of guidelines for designing, implementing, and testing optical systems. It offers fundamental insights as well as practical application/implementation of optical transmission systems. Both detection systems and coherent systems are described and many other techniques are presented both theoretically and experimentally in the form of numerous demonstration systems and detailed measurements, including bit-error rate, signal-to-noise ratio, crosstalk, etc. An engineering design and development are maintained through most of the sections. An attempt is made to include as much recent material as possible so that the participants are exposed to the recent advances in the field. In each section, we have provided practical problems that deal with "real-world" situations, and detailed references..No background communications prerequisites are expected for this course.
This course is provided into eight parts:
1. Overview of lightwave
2. Semiconductor laser sources and photodetectors.
3. Optical fibers, cables, and connections.
4. Fiber equipment measurements.
5. Optical components and sensors for communication applications.
6. System design and performance
7. Direct detection and coherent lightwave systems
8. Multichannel optical systems
Hung D. Nguyen, Ph.D.
Dr. Nguyen is a senior engineer for the Space Communication Division of NASA
Glenn Research Center at
This course is suitable to anyone who is already engaged in or wishing to enter the area of optical communications.
Overview of lightwave
Ray theory transmission
Refraction and reflection
Critical angle, numerical aperature, refractive index difference
Reflection coefficient effect of TE and TM polarization
Types of polarization states
- Linear, circular, and elliptical polarizations
Jones matrix representations for
- Linear, circular, and elliptical polarization
Field representations of polarization
Which applications require polarization
Polarizing optical systems
- Linear and rotator polarizer
- Wave retarder : Quarter-wave and half-wave retarder.
- Perfect and partial-perfect coherence.
- Coherent time
- Coherent length
What optical systems require coherent states
- Irradiance of coherent and incoherent waves
- Single and multiple slits
In class exercise
Semiconductor Laser Sources and Photodetector.
What are semiconductor sources and transmitter ?
Operating characteristics of light emitting diode (LED)
Types of LEDs
- Surface emitting
- Edge emitting
LED modulation and power output
Spectral width output
Tradeoff between surface-emitting and edge-emitting LED
- Modulation response, carrier lifetime, rise time
- Output power at DC and AC state
- Direct modulation of injection current.
Operation of semiconductor laser
Types of semiconductor laser
Radiation pattern of laser
- Rise and fall time.
- Threshold current.
- Spectral width.
Tradeoff comparison between double heterostructure and buried lasers
Characteristics of double and buried lasers
Principle of optical cavity resonator
- Free spectral range
- Mode spacing
- Number of longitudal modes
LED and laser emissions
Trade-off comparison between laser and LED
Types of laser diode
- Distributed feedback
Modulation of laser
Pulse, intensity, and external modulation.
What are detector and receiver ?
- Quantum efficiency
- Conversion gain
- Rise time
- Minimum detectable signal
- Noise equivalent power
Dynamic range, responsitivity, cutoff wavelength, current gain
Linear operation, dark current, signal current, bandwidth, gain factor
Types of noise
- Thermal noise
- Dark current noise
- Shot noise
- Signal to noise ratio with/without external gain
Types of photodiode
- PIN (Positive-intrinsic negative) photodiode
- APD(Avalanche photodiode)
Characteristics of photodiode
- PIN: Silicon, Germanium, InGaAs
- APD: Silicon, Germanium, InGaAs
Speed of response
Tradeoff between PIN and Avalanche detector
In class exercises
Optical Fiber, Cables, and Connections.
Construction of fibers
Types of fibers
- Step-index fiber
- Graded index fiber
- Single-mode fiber
- Glass fiber
- Plastic-clad-silica fiber
- Plastic fiber
Dimension of fibers
Advantages/benefits of fibers
- Intramodal dispersion: Material and waveguide.
- Intermodal dispersion: Modal effect
Limited data rate
Methods to reduce dispersions
Characteristics of step-index, graded-index, and single-mode fibers
- Delay difference, pulse broadening, bandwidth-length product
- Refractive index profile, normalized frequency
Types of attenuation
- Rayleigh scattering
- Step-index type
- Graded-index type
- Structure and performance characteristics
- Refractive index profile
- Normalized frequency
- Number of guided modes.
- Polarization-preserving fiber
- Structure and performance characteristics
- Cut-off wavelength.
- Beat length
Common fiber applications
In class exercise
Conditions of fiber cables
Maximum pulling and operating load
Maximum radius bending
Mechanical resistances: Impact, crush, and flex
Main parts of cable
Core, cladding, silicone coating.
Buffer, tape, strength member, outer jacket.
Considerations of cable
Moisture and chemical exposure
Two types of materials.
Dielectric and nondielectric cables
Riser and plenum materials
Three different buffering systems
Two types of buffer coating.
Single optical fiber
Trunk transmission links
High density interconnection.
Indoor and outdoor cable
Routed to multiple locations
UV and weather resistance.
Loose tube type.
Military tactical cable
Communications and sensing cables
Cables for different applications.
Submarine and undersea.
Metropolitan area networks
Connectors and Splices
Requirements of good connectors
Mutimode and singlemode connectors
Types of connectors
Types of splicing
Loss in fiber-to-fiber connection
Gap between ends
Types of loss
Insertion, excess, return, and coupling loss
Fiber Equipment Measurements.
Optical source for loss measurements.
- Mode stripper.
- Mode filter.
Fiber loss measurement.
- Cut back method.
Localization of near-end faults.
- Time domain method.
- Frequency domain method
Attenuation as a function of source wavelength.
Bandwidth and dispersion.
Optical component loss measurement.
Scattering loss measurement.
Free space power measurement.
Numerical aperture measurement.
Laser line-width measurement
Return loss measurement.
Laser chirp measurement.
Modulation bandwidth measurement.
Bit error rate.
Optical time-domain reflectometer. (OTDR)
Link loss measurements
Reflecance and return loss measurement
Breaks in cable
Measurement of coherence time and length
Components required for optical sensor
Types of optical sensors
Variable fiber coupling
Back reflected light
Variations of detection
Advantages of optical sensors
Two classes of sensing devices
Vertical, and angular effect
Chemical in water effect
Multimode optical fiber sensors
Types of measurements
Single mode fiber sensors
Types of interferometer.
In class exercise
Optical Components and Sensors for Communication Applications.
Passive and active devices.
Basic operations of couplers.
Types of loss.
- Throughput , tap, isolation , insertion, directionality, and excess loss.
Types of waveguide couplers.
- Y-junction , splitter, merging couplers.
Types of fiber couplers.
- T coupler: Grin rod and beamsplitter lenses.
- Star coupler: Transmission and reflective star
- Directional coupler.
- Wavelength selectivity.
- Wavelength division multiplexer.
- Micro-optical coupler.
- Fiber coupler.
Directional coupling waveguides.
Single mode optical 1 x N star coupler
Grin-rod lens and interference filter
Concave grating filter
Optical path bending device
Interferometer wavelength filter.
Acoustic-optical tunable filter
Semiconductor distributed-feedback filter
Modulation of light: Direct and external modulation
Traveling wave modulator
Phase-matched polarization modulator
Optical switching devices.
Directional switching coupler
Internal reflection switch
Microelectromechanical systems (MEMS) switch
Phase modulator integrated with polarizer
TE - TM mode converter.
TE/TM polarization splitter.
Photoelastic waveguide and polarizer
Semiconductor and doped-fiber amplifier
Traveling wave amplifier
Displacement sensor using Michelson interferometer.
Evanescent field sensor.
Gyroscope on chip and substrate.
Electric field sensor.
System Design and Performance.
System design considerations
- Short distance- LAN system.
- Medium distance- Inter-central office system.
- Long distance- Toll-office trunk system.
Influence of system choice
Bandwidth, loss budget, size and weight consideration,
system cost, reliability, distance of operations.
Launched power, fiber choice, component loss, total channel loss
Signal-to-noise ratio, system rise time, maximum bit rate
Required safety margin, receiver sensitivity.
Fiber transmission systems.
Optical/digital transmission link.
Components of fiber link.
Bandwidth limited by dispersion.
Maximum transmission distance limited by dispersion.
System power budget.
Direct Detection and Coherent Lightwave Systems.
Coherent light transmission
Components for coherent system.
Optical/Digital transmission link.
- Transmission medium.
- Light-emitting diode.
- Surface-emitting LEDs.
- Edge-emiting LEDs
- Laser diode.
- Fiber-loss calculation.
- Bandwidth limited by dispersion.
- Maximum transmission distance limited by dispersion.
Types of fiber optic link.
- Direct modulation link.
- Medium distance
- Chirping problem
- Limited bandwidth
- External modulation link.
- Long-haul distance capacity.
- Low chirping problem.
- Wide bandwidth
Market demands/Advantages of fiber optic link.
- Analog modulation.
- Amplitude (AM)
- Phase (PM)
- Frequency (FM)
- Digital modulation.
- Amplitude shift keying format.
- Phase shift keying format.
- Frequency shift keying format
- Intensity-modulation scheme.
- Analog optical receiver.
- Digital optical receiver.
- Heterodyne detection.
- Homodyne detection.
- ASK synchronous heterodyne scheme.
- ASK asynchronous heterodyne scheme.
- DPSK asynchronous heterodyne scheme.
- FSK asynchronous heterodyne scheme.
Comparison between direct and coherent detections.
Bit error rate and receiver sensitivity with various modulation formats.
- ASK receiver
- PSK receiver.
- FSK receiver.
- Optical amplifier.
Multichannel Optical Systems.
System integration process.
- Point-to-point link.
- Point-to-multipoint: Broadcast.
- Multipoint-to-point: Network.
- Half-duplex transmission
- Full-duplex transmission.
Categories of transmission systems.
- Short, medium, and long distance.
Broadband network architecture.
- Master hub.
- Link hub
Bi-directional multiplexing transmission.
- Space division.
- Wavelength division.
- Wavelength splitter.
- Polarization division.
- Optical circulator.
Types of optical transmission.
- Time division multiplexing system.
- Wavelength division multiplexing system.
- Frequency division multiplexing system.
- One direction.
- Two direction.
- Electrical multiplexer.
- Optical multiplexer.
Photonic RF mixer /transmitter/receiver.
CATV system architecture
Central office systems.
- Central office network topology.
Undersea lightwave system.
Hung Nguyen, Ph.D.
INFORMATION ON REGISTRATION.
TIME : 8:00 – 5:00
FEES : $1,200.
3-way of Payment:
1.Check payable to : Lightwave Technology Corp. (Mail to: Lightwave Technology Corp.,
2. Purchase order attached : #
3. Invoice my company: Attention :
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DEAD LINE REGISTRATION
Registration by regular or electronic mail must be received at least 14 days before the first day of class (course date)
Full refund if class is cancelled. Otherwise, 20% refund less than 7 days before the first day of class. No refund is granted the first day of class.
Lightwave Technology Corp. reserves the right to cancel class if there is inadequate enrollment.