Diodes and Bipolar Junctions

Diodes are two-terminal electrical components that allow the current to flow in one direction. Laser diodes can create lasting conditions when pumped with electrical current at the diode junctions. Laser diodes are used in different settings, such as the medical industry, especially in surgeries and dermatological treatments. They are also used in laser printers and scanners, while low-power diode lasers with quality beams are used to read and write data in media such as BLU-RAY. Lastly, they are used in metal welding and optical fiber communications. Diode lasers are widely used because they are electrical efficient, have a good life span, and are reliable when used well. They are also cheap and compact compared to other laser types since they can be used for low- and high-power applications (Gentec, 2022).

Bipolar junction transistors are there-terminal semiconductor devices with two p-n junctions that magnify signals. BTJs can be used in saturation, active and cut-off regions, which are used as amplifiers in active or linear areas. It can be used for switching in three ways: common base, common collector, and common emitter. At the emitter-base junction in the common base, the voltage is supplied and obtained at the base-collector junction. The base voltage is usually grounded to make a common base between the input and output signals. At the common collector, input is applied at the base terminal, and output is drawn from the emitter terminal. For amplification to take place, the transistor must have a high current gain. Lastly, an input signal is applied between the base and emitter at the common emitter, and the output is collected at the emitter and collector (Electrical Volt, Nd.). This creates an excellent amplification since the combination has maximum power gain. Common emitter arrangement is common in most transistors since it provides appropriate power and current used in amplification. Bipolar junction transistors are used as foundations in electrical circuits that need audio, current, or voltage amplification.


Electrical Volt (Nd.). Bipolar Transistor (BTJ) as an Amplifier. Electrical Volt.

Gentec (2022). What are diode lasers and where do we use them? Gentec.