What are the different types of photodetectors?

What are the different types of photodetectors?

Common Types of Photodetectors

• p-n Photodiodes.
• p-i-n Photodiodes.
• Avalanche Photodiodes.
• MSM Photodetectors.

What does a photodetector measure?

Photodetectors measure photon flux or optical power by converting the absorbed photon energy into electrical current.

What is a Photoreceiver?

Photoreceivers are based on the same types of semiconductor photodiodes used for power sensors (see Photodiode Sensor Physics) and camera-based beam profiling (see Laser Beam Profile Measurement).

What are the applications of photodetectors?

A photodetector is an opto-electronic device that converts a light signal into an electrical signal via various photo-related phenomena. Photodetectors are extensively used in many applications such as remote sensing, thermal imaging, environmental monitoring, and communication systems.

What is the principle of photodetector?

Photodetection converts an optical signal into a signal of another form. Most photodetectors convert optical signals into electrical signals that can be further processed or stored. All photodetectors are square-law detectors that respond to the power or intensity, rather than the field amplitude, of an optical signal.

What are the characteristics of photodetectors?

Photodetectors are characterized by certain key parameters. Among them are spec- tral response, photosensitivity, quantum efficiency, dark current, forward-biased noise, noise equivalent power, terminal capacitance, timing response (rise time and fall time), frequency bandwidth, and cutofffrequency.

What type of semiconductor is used for Photodetection?

Graphene/silicon photodetectors Graphene is coupled with silicon quantum dots (Si QDs) on top of bulk Si to form a hybrid photodetector. Si QDs cause an increase of the built-in potential of the graphene/Si Schottky junction while reducing the optical reflection of the photodetector.

What is required for good performance of photodetector?

Depending on the application, a photodetector has to fulfill various requirements: It must be sensitive in a certain spectral region (range of optical wavelengths). In some cases, the responsivity should be constant or at least well defined within some wavelength range.

What are the major requirements of a photodetector for a better performance?

What are the characteristics of photodetector?

What are the main parameters to consider in selecting photodetectors?

Some parameters to consider are: Light power level. Wavelength range of incident light. Electrical bandwidth of the detector amplifier.

How do you measure responsivity of a photodetector?

You can measure the responsivity of a silicon photodiode by illuminating the device with a known amount of laser power and then measuring the output voltage developed across a bias resistor. You must first characterize the light sources you will use by measuring the power in the beams.

What are the various factors which affect the response time of a photodetector?

Photodetector Response Time

• The response time of a photodetector with its output circuit depends mainly on the following three factors:
• 1- The transit time of the photocarriers in the depletion region.
• 2- Diffusion time of photocarriers outside depletion region.
• 3- RC time constant of the circuit.

What is photodiode sensitivity?

Definition: The sensitivity of a photodiode is the ratio of amount of current flow with unit light irradiance. It can expressed as per equation below. The dark current can be minimized in order to enhance the sensitivity of the photodiode.

What is the significance of responsivity of photodetector?

Responsivity measures the input–output gain of a detector system. In the specific case of a photodetector, it measures the electrical output per optical input. A photodetector’s responsivity is usually expressed in units of amperes or volts per watt of incident radiant power.