Femtosecond Lasers:

A pulsed laser is any laser that does not emit a continuous-wave (CW) laser beam. Instead, they emit light pulses at some duration with some period of ‘off’ time between pulses and a frequency measured in cycles per second (Hz). There are several different methods for pulse generation, including passive and active q-switching and mode-locking. Pulsed lasers store energy and release it in these pulses or energy packets. This pulsing can be very beneficial, for example, when machining certain materials or features. The pulse can rapidly deliver the stored energy, with downtime in between, preventing too much heat from building up in the material. If you would like to read more about q-switches and the pros and cons of passive vs active q-switches, check out this blog “The Advantages and Disadvantages of Passive vs Active Q-Switching,” or check out our Overview of Pulsed Lasers section on our Lasers 101 Page!

There are actually numerous laser types that work well for various LIDAR and 3D Scanning applications. The answer comes down to what you want to measure or map. If your target is stationary, and distance is the only necessary measurement, short-pulsed lasers, with pulse durations of a few nanoseconds (even <1ns) and high pulse energy are what you’re looking for. This is also accurate for 3D scanning applications (given a stationary, albeit a much closer target), but select applications can also benefit from frequency-modulated, single-frequency (narrow-linewidth) fiber lasers. If your target is moving, and speed is the critical measurement, you need a single-frequency laser to ensure accurate measurement of the Doppler shift. If you want to learn more about the various forms of LIDAR and the critical laser source requirements, check out our LIDAR page for a list of detailed articles, as well as all the LIDAR laser source products we offer. Get more information from our Lasers 101, Blogs, Whitepapers, FAQs, and Press Release pages in our Knowledge Center!

Similar to laser hair removal, laser tattoo removal utilizes a process known as selective photothermolysis to target the embedded ink in the epidermis and dermis.  Photothermolysis is the use of laser microsurgery to selectively target tissue utilizing specific wavelengths of light to heat and destroy the tissue without affecting its surroundings.  In laser tattoo removal this is accomplished by using a focused q-switched laser with a fluence of approximately 10 J/cm², to heat the ink molecules locally.  Since the q-switched laser’s pulse duration (100 ps to 10 ns) is shorter than the thermal relaxation time of the ink molecules it prevents heat diffusion from taking place.  In addition to minimizing damage to the surrounding tissue, this rapid localized heating results in a large thermal differential, resulting in a shock wave which breaks apart the ink molecules. If you would like more details on pulsed lasers for tattoo removal applications, see our Aesthetics Lasers page here! Get more information from our Lasers 101, Blogs, Whitepapers, and FAQ pages in our Knowledge Center!

Multiphoton excitation requires high peak power pulses. Previously, wavelength tunable Ti:Sapphire lasers dominated this area, leading to the development of standard methods using a conventional pulse regime with typically 100-150 fs pulse duration, 80 MHz repetition rate, and watt level average power with specific wavelengths such as 800 nm, 920 nm, and 1040-1080 nm. Recently, femtosecond pulsed fiber lasers have started becoming the optimal solution due to their low relatively low fluence, limiting damage to living samples. Other advantages provided by fs fiber lasers include a more attractive price point, very compact and robust format, high electrical efficiency, high reliability, and less maintenance of cost of ownership. If you would like more details on why fs fiber lasers are becoming the optimal choice for multi-photon excitation applications, read this article: “Higher Power fs Fiber Lasers to Image Better, Deeper & Faster.” Get more information from our Lasers 101, Blogs, Whitepapers, FAQs, and Press Release pages in our Knowledge Center!

There are a wide variety of q-switch technologies, but the technique as a whole can be broken down into two primary categories of q-switches, passive and active. Active q-switches could be a mechanical shutter device, an optical chopper wheel, or spinning mirror / prism inside the optical cavity, relying on a controllable, user set on/off ability. Passive q-switches use a saturable absorber, which can be a crystal (typically Cr:YAG), a passive semiconductor, or a special dye, and automatically produce pulses based on it’s design. Both passive and active q-switching techniques produce short pulses and high peak powers, but they each have their pros and cons. When choosing between actively q-switched and passively q-switched lasers, the key is to understand the tradeoffs between cost/size and triggering/energy and decide which is best for your particular application. Read more about these tradeoffs in this article: “The Advantages and Disadvantages of Passive vs Active Q-Switching.” Get more information from our Lasers 101, Blogs, Whitepapers, FAQs, and Press Release pages in our Knowledge Center!

A laser source used for LIBS must have a sufficiently large energy density to ablate the sample in as short a time possible. Typically, pulsed DPSS lasers take center stage here. However, it’s been shown that pulsed fiber lasers can also be a great option. For example, you could utilize fiber lasers to measure detection limits as low as micrograms per gram (µg/g) for many common metals and alloys, including aluminum, lithium, magnesium, and beryllium. Analytical performances showed to be, in some cases, close to those obtainable with a traditional high-energy Nd:YAG laser. The beam quality of fiber lasers, in conjunction with longer pulse widths, resulted in significantly deeper and cleaner ablation craters. If you want to learn more about LIBS and ideal laser sources, check out either this blog: “OEM Fiber Lasers for Industrial Laser Induced Breakdown Spectroscopy,” or this blog: “Laser Induced Breakdown Spectroscopy (LIBS) in Biomedical Applications.” Get more information from our Lasers 101, Blogs, Whitepapers, FAQs, and Press Release pages in our Knowledge Center!

There are many different types of laser designation systems used by the military today. Still, they all share the same basic functionality and outcome. At a glance, the laser requirements seem relatively straightforward. The laser needs to be invisible to the human eye, and it needs to have a programmable pulse rate. Still, when you look in more detail, many small factors add up to big problems if not appropriately addressed. Excellent divergence and beam pointing stability, low timing jitter, and rugged, low SWaP design are all critical features of a good laser designation source. Read more on these critical features in this article: “What are the Critical Laser Source Requirements for Laser Designation?” Get more information from our Lasers 101, Blogs, Whitepapers, FAQs, and Press Release pages in our Knowledge Center!