Fiber Optic Transmissions
A fiber optic transmitter is a device that converts an electrical
analog or digital signal into a corresponding optical signal. It is one of the
components of fiber optics technology that uses long flexible glass-like fibers
(optical fibers) for transmitting light signals over long distances. The other
two components of the fiber optic transmission system are the fiber optic cable
and the optical receiver. Some systems also possess the optical regenerator,
which may be essential to boost the degraded light signal (for long distances).
The fiber optic transmitter includes a light emitting diode (LED),
or a solid state laser diode, and signal conditioning electronics. Usually, the
transmitter processes the signals of wavelengths of 850, 1310, or 1550 nm. LEDs
are broadly used for short to moderate transmission distances, while laser
diodes are meant for transmitting signals over long distances. Compared to
LEDs, laser diodes can couple many times more power to optical fiber.
Separate fiber optic transmitters are available for single-mode
fibers and multi-mode fibers. Also, some transmitters allow connecting both
single mode and multimode cables in them. Biconic, D4, ESCON, FC, FDDI, LC,
Loopback, MTP, MT-RJ, MU, SC, SMA, and ST are some of the common connectors.
Data rate (data bits transmitted per second), transmitter rise time
(the time needed for a signal to change from a defined 10% to 90% of full
power), wavelength (the output wavelength of the transceiver), spectral width
(the spectral width of the output signal), and maximum optical output power are
considered to be the important performance specifications while selecting a
fiber optic transmitter. The speed of a transmitter is expressed in terms of
its rise time.
To specify a fiber optic transmitter, it is necessary to refer to
its operating temperature, signal inputs (such as TTL, ECL, CMOS video, and
RF), pigtail, focusing lens (improving coupling between the transmitter and the
fiber), and stand-alone.
More Questions:
1. What is software testing? Explain the purpose of testing.
2. Explain the concept of quality.
3. Explain defect prevention.
4. Explain different methods available in
white box testing with examples.
5. Explain the use of decision tables in
testing.
6. Write a note on Quality Assurance in software
support projects.
7. Explain the main purpose of SQA plan.
8. Explain the main objectives of black box
techniques.
9. Develop an integration testing strategy
for any of the system that you have
implemented already. List the
problems encountered during such process.
10. Explain the use of McCall’s
Factor-Criteria-Metric Model.