A helium cadmium laser, also known as a HeCd laser, is a type of gas laser that uses a mixture of helium and cadmium gases as the active laser medium. It produces a laser beam with a wavelength of 442 nanometers in the blue part of the visible spectrum, and at 325nm which is in the ultraviolet (UV) spectrum.
The HeCd laser works by using an electrical current to excite the helium and cadmium gases inside a sealed tube, causing them to produce photons (particles of light). These photons are then amplified and emitted as a beam of coherent light through a partially reflective mirror at one end of the tube.
One of the main advantages of the HeCd laser is its high efficiency, with up to 50% of the electrical energy used being converted into laser energy. It also has a very narrow beam width, making it useful for applications that require precise targeting.
The HeCd laser is commonly used in a variety of scientific and industrial applications, including spectroscopy, microelectronics manufacturing, and laser machining. It is also used in some medical procedures, such as laser eye surgery, due to its ability to produce a precise, highly focused beam of UV light.
Overall, the helium cadmium laser is a valuable tool for a wide range of applications that require a highly efficient, precise, and powerful source of UV laser light.