The He-Ne laser, also known as the helium-neon laser, is a type of gas laser that produces coherent light in the visible and infrared regions of the electromagnetic spectrum. Here is some information about the He-Ne laser:
Principle of operation: The He-Ne laser operates on the principle of population inversion. When helium and neon atoms are excited by an electric discharge, they undergo collisions that cause some of the helium atoms to become excited and transfer their energy to the neon atoms. This results in a population inversion, where the upper energy level of the neon atoms is more populated than the lower energy level.
Wavelength: The He-Ne laser emits light at a wavelength of 632.8 nm, which is in the red part of the visible spectrum. This wavelength is commonly used in laser printers, barcode scanners, and other applications.
Power output: The power output of a He-Ne laser is typically in the milliwatt range, although higher-power versions are also available.
Beam quality: The He-Ne laser produces a highly coherent, low divergence beam with a Gaussian intensity profile.
Applications: The He-Ne laser has many applications, including in spectroscopy, interferometry, and holography, and as a reference laser for other applications. It is also used in medicine for dermatological treatments.
Lifetime: The lifetime of a He-Ne laser is typically several thousand hours, although this can vary depending on the specific laser design and operating conditions.
Safety: He-Ne lasers emit visible light that can cause eye damage if viewed directly, so appropriate safety precautions should be taken when working with these lasers.
