What to look for when selecting a laser

Lasers are one of those things that everybody knows about, but few know how they work. If you are looking for a laser and just don’t know where to start, here are some tips that might point you in the right direction.

Lasers have been used for many different applications such as safety barriers, pointers, levelers, cutters, surgical devices and more. Just to get started, it is important to understand a few things about how lasers work.

A laser is a focused beam of light. Light travels in waves much like sound travels in waves. This means that as it travels, its intensity goes up and down from a base value to a peak value. This fluctuation is measured either in time Hertz (Hz) or in wavelength (m). For the purpose of laser selection, wavelength measured in nanometers is utilized.


The human eye can perceive light approximately in the range of 200nm-900nm, but the average eye would see closer to the 350nm-750nm range. Different colors are perceived within certain wavelength ranges along the visible spectrum while beyond that spectrum is invisible light. Some applications such as safety barriers and other through beam devices use lasers that are in an invisible wavelength. If multiple wavelengths are being perceived at once, it is seen as white light.


The strength of a laser is determined by the amount of power that is behind it, the length of the housing, and the type and focus of the lens used. If you’re building your laser from scratch a laser diode would be used and would need a housing or module and lenses. Otherwise a complete laser module can be used. While lasers used for cutting, boring or medical applications are high powered and use specialized lenses, Digi-Key Electronics is a great source for low to mid power laser diodes and modules.

So, to summarize, when selecting a laser, the important things to consider are whether you need a simple diode or a finished module, the wavelength to determine the color, and the power rating measured in Watts (this is generally a capacity rating indicating the maximum power the diode and its leads can handle). One more thing to consider is whether the module selected will have a focusing feature such as VLM-650-02 LPA which allows the width of the beam to be selected.

Now that there is a better understanding of how to select a laser, all that is needed is to decide which kind of shark to get.