Pulsed Lasers

How to Select a Pulsed Laser

Welcome to our ‘How To Select A Pulsed Laser’ section, designed to help you down-select to an appropriate range of Pulsed Laser options, based on your unique requirements. In short, we explain how we define and organize our vast product portfolio, and how you can use our filters and product table to quickly find viable options to suite your needs.

Pulse Width Selection:

If you need a pulsed laser, a good starting point would be filtering for Pulse Width. Here we will explain our Pulse Width categories and how we define the differences. Finally, we provide some examples of typical Pulsed Laser applications, per category.

Femtosecond Lasers:

Femtosecond (fs) Lasers – in the Ultrafast Laser category – generate incredibly high peak pulse powers, extremely short pulse widths, and allow for what is known as ‘Cold Ablation.’ In short, cold ablation allows for material to be removed without heating the residual matter. Therefore, these lasers produce minimal heat affected zones (HAZ), splatter, or significant recast, and typically eliminates the need for post processing. Furthermore, the high peak power and short pulse width of Femtosecond Lasers is ideal for a wide range of applications. For example, especially for Non-Linear Spectroscopy, Two-Photon/Multi-Photon Microscopy, Second Harmonic Generation (SHG), and Micromachining of many materials, including metals, ceramics, polymers, composites, coatings, glass, plastics, diamonds, and PET. In short, on a watt-to-watt basis, quality, material penetration depth, and throughput increase as the pulse duration decreases. Finally, material to wavelength dependency is lower at these shorter pulse durations.

Picosecond Lasers – < 300ps and > 300ps:

Under 300 Picosecond Lasers (shorter picosecond pulses – e.g. ≈10ps and less) are also considered Ultrafast Lasers, producing results similar to those of a Femtosecond Laser, generating high peak powers and short pulse widths, providing cold ablation processing, with minimal HAZ, typically at a lower price point than a Femtosecond Laser.

Over 300 Picosecond Lasers (sub-nanosecond pulses) tend to act more like their Nanosecond Laser counterparts. Therefore, the high peak power and short pulse widths of >300 Picosecond Lasers are ideal for a wide range of applications. For example, for material processing and machining applications, such as Laser Texturing, Trimming, and Drilling.

Nanosecond Lasers:

Nanosecond (ns) Lasers, sometimes referred to as Nanolasers, are the most common category of q-switched Pulsed Lasers used today. In short, these lasers generate high peak powers and short pulse widths. However, the pulses are nowhere near as short, nor do they reach the peak power levels of their Ultrafast Laser counterparts. Therefore, the high peak power and short pulse widths of these lasers are ideal for a wide range of applications. For example, Material Processing, LIBS, Laser Designation, and Laser Marking. To clarify, unlike Femtosecond and Picosecond Lasers, Nanosecond Lasers induce heat into a material to remove or alter it. Finally, Nanosecond Laser applications are often wavelength specific, due to material absorption characteristics in this pulse regime.

Wavelength Selection:

Many applications are wavelength specific due to a sample’s absorption characteristics, or a systems detection limitation. Therefore, we offer a wide selection of wavelengths for our Pulsed lasers. Firstly, we have UV wavelengths, good for LIBS, Fluorescence Lifetime, and Raman Spectroscopy. Secondly, we have IR wavelengths from NIR to LWIR, good for Gas Sensing, LIDAR, and Laser Designation, and everything in between. In conclusion, if you know what wavelength you need, this can be a good way to filter out unnecessary options.

Repetition Rate:

When it comes to the Repetition Rate, we group our lasers into the categories: Hz (1 – 999Hz), kHz (1kHz – 999kHz), and MHz (1MHz – 999MHz). In short, Pulsed Lasers with lower repetition rates (e.g. Hz range) exhibit lower peak pulse powers and longer pulse widths. However, higher repetition rates (e.g. MHz) provide extremely high peak pulse powers and much shorter pulse widths, depending on a couple factors, like duty cycle.

Power  Selection:

Power is a function of pulse energy and repetition rate. Therefore, if you have a defined pulse energy requirement, you can easily calculate what Power you would have at any given repetition rate (Power = Energy / Rep. Rate). Finally, you can use the ‘Power Selection’ filter to down select to a more appropriate range of options.

Energy  Selection:

Energy is a function of power and repetition rate. Therefore, if you have a defined average power requirement, you can easily calculate what Energy you would have at any given repetition rate (Energy = Power / Rep. Rate). Finally, you can use the ‘Energy Selection’ filter  to down select to a more appropriate range of options.

Types:

For your convenience, and to help increase your in-site search results, we have grouped our pulsed laser offerings into segments, or “Types,” which you can read more about by clicking the links below.

Series:

Finally, if you happen to know of a particular series of lasers, you may simply filter to see all pulsed options for that series.

If You Would Like Some Assistance:

Other important considerations for laser selection are the operating environment (Industrial, Mil, Space, Medical, R&D), for example, allowable laser footprint, power consumption, efficiency, ruggedness, cooling, and cost. In short, these factors further narrow your pulsed laser options and are often the primary deciding factors for laser selection. Finally, for help in identifying a suitable pulsed laser for your application, contact info@rpmclasers.com, call us at 636.272.7227, or click the button below to fill out a contact form!

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