Multi-mode Laser Diodes: Introduction A laser diode is an electrically pumped semiconductor laser that produces coherent light when the current flows through a p–n junction Laser diodes are available in the following wavelength ranges: UV (200 - 389 nm), violet (390 - 419 nm), blue (420- 499 nm), green (500–559 nm), red (620–699 nm), and IR (700 - 2,150 nm) Laser diodes have single-mode and multi-mode design configurations. Among these, multi-mode laser diodes have a larger emitting area, which offers higher power. Also, it offers a wide surface area at the facet, which reduces the intensity of catastrophic optical damage. These multi-mode laser diodes are ideal for use in several industrial applications including laser cladding, fiber laser pumping, surface-enhanced Raman spectroscopy, machine vision, and communication Moreover, low rise time and high pulse energy of multi-mode laser diodes make them a preferred choice for use in high-resolution sensing application...