Continuous Wave Lasers: Understanding the Basics

Laser technology as we know it was first envisaged on a park bench in Washington in 1951, when Charles Townes thought-up the concept of microwave amplification by stimulated emission of radiation (MASER). Within ten years, this idea had germinated, yielding the first solid-state laser with a ruby gain medium. Sixty years of near non-stop development and innovation has led to a plethora of laser systems using different gain mediums, amplification techniques, and so on. But the most fundamental differentiating factor between different types of lasers is whether they are pulsed or continuous wave (CW).


What is a Continuous Wave Laser?

Continuous wave lasers have a nominally constant output over a set interval. This means that key beam parameters (power output, intensity, etc.) remain constant throughout the beam’s duration. The phrase continuous-wave refers to the coherent beam of monochromatic light emitted by the gain medium, which also determines the laser wavelength. That first solid-state laser used a synthetic ruby to produce visible light with a deep red colour, corresponding to a wavelength of approximately 694 nanometres (nm).


Many CW lasers today still use crystal gain mediums. Titanium-sapphire, or Ti:sapphire, and neodymium-doped yttrium aluminium garnet (Nd:YAG) are among the most popular gain crystals for continuous wave systems. But intensive research and development over the years has also yielded a raft of gas and fibre lasers, broadening the scope of continuous wave lasers significantly.


How do CW Lasers Differ from Pulses Lasers?

The difference between a continuous wave and a pulsed wave is that the former refers to an uninterrupted beam while the latter describes a laser that is emitted in short bursts.


Historically, CW lasers have proven superior in terms of their stability and power output with short laser pulses proving incapable of sublimating materials with any degree of efficiency. Chirped pulse amplification (CPA) has largely resolved this issue, but the stability of continuous wave lasers over operating periods extending from a few microseconds to several weeks still makes them a competitive solution for industrial applications.


Continuous Wave Lasers from Laser Quantum

Laser Quantum is one of the industry leading developers of high quality solid-state lasers designed with end users in mind. Our systems are based on a commitment to performance excellence over extended life cycles, protecting your investment throughout rigorous use cycles and in rugged conditions.


Explore our lasers to find specific products suitable for your application area. Or, if you have any questions for the Laser Quantum team, simply contact us today.