What is meant by intensity modulation?
Table of Contents
Definition of intensity modulation : modulation in which the brightness of the light displayed on a cathode-ray tube varies with the intensity of the signal.
What is intensity modulated direct detection?
Intensity modulation and direct detection (IM/DD) is a cost-effective optical communication strategy which finds wide applications in fiber communication, free-space optical communication, and indoor visible light communication.
What is meant by the intensity modulation of an optical source?
In optical communications, intensity modulation (IM) is a form of modulation in which the optical power output of a source is varied in accordance with some characteristic of the modulating signal.
What is subcarrier intensity modulation?
Subcarrier intensity modulation with direct detection is a modulation/detection technique for optical wireless communication sys⁃ tems, where a pre⁃modulated and properly biased radio frequency signal is modulated on the intensity of the optical carrier.
What is frequency modulation and demodulation?
Frequency Modulation Tutorial Includes: FM demodulation is a key process in the reception of a frequency modulated signal. Once the signal has been received, filtered and amplified, it is necessary to recover the original modulation from the carrier. It is this process that is called demodulation or detection.
How is frequency modulation done?
To generate a frequency modulated signal, the frequency of the radio carrier is changed in line with the amplitude of the incoming audio signal. When the audio signal is modulated onto the radio frequency carrier, the new radio frequency signal moves up and down in frequency.
Which modulation is used in optical communication?
Fiber-optic telecommunication systems use pulse-code modulation. Information is transmitted as a series of pulses. The digital pulse-code-modulated signal is coupled into a fiber.
How can the irradiance of the transmitted optical signal be modulated?
The intensity of the light wave traveling through an optical fiber can be modified by microbending of the optical fiber, by a change in coupling of the fiber with the surrounding medium, or the fracture of the optical fiber.
What is the need of frequency modulation?
Frequency modulation (FM) Because the frequency of a radio wave is less vulnerable to noise than the amplitude, FM was originally introduced to reduce noise and improve the quality of radio reception. In order to accomplish this, FM radio signals have bandwidth several times that of AM signals.
What is frequency modulation and the equation of a FM modulated wave?
Frequency Modulation Equation The FM equation include the following. v = A sin [ wct + (Δf / fm) sin wmt ] = A sin [ wct + mf sin wmt ] A = Amplitude of the FM signal. Δf = Frequency deviation.
What is intensity modulated radiation therapy?
Intensity Modulated Radiation Therapy (IMRT) is a computer-based method of planning for, and delivery of generally narrow, patient specific, spatially and often temporally modulated beams of radiation to solid tumors within a patient.
What is the difference between intensity modulation and field modulation?
Although intensity modulation has been widely used in optical communication systems, complex optical field modulation has been shown much more efficient in terms of transmission capacity as both the intensity and the optical phase can be used to carry information.
What is intensity modulation in optical fiber?
Intensity-Based Fiber Sensors The intensity modulation (IM) of light is a simple method for optical sensing. There are several mechanisms that can produce a measurand-induced change in the optical intensity propagated by an optical fiber. Perhaps the simplest type of IM fiber sensor is the microbend sensor shown in Figure 2.
What is intensity modulation/direct detection?
Most commercial optical communication systems use intensity modulation/direct detection (IM/DD) schemes in which the intensity of semiconductor lasers is modulated to carry the information and the optical signal is detected directly by a photodiode.