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Laser Diode Fundamentals – Fiber Coupling 2

In the last blog post of our laser diode fundamentals series, we discussed the basics of fiber optics concentrating on two key parameters; core diameter and numerical aperture. In this blog post, we are going to turn the discussion to fiber coupling techniques conventionally used in laser diode packaging including butt coupling, ball lens coupling, and intermediate co… Read More

Micromake Machining Laser

Last fall, we published a blog titled “Micromachining Lasers for Anti-Counterfeiting,” where we explored how laser micromachining can be used to embed microscopic two-dimensional identification codes directly onto the item of interest.   In addition to discussing the fundamentals of micromachining in that blog, we highlighted the MicroMake system from Bright Solutions, including how its short pulse width and high pulse repetition rate facilitate ablation to produce ultra-high-resolution machining… Read More

The Basics of Microchip Laser Harmonics

Microchip lasers have been around since 1989 when they were first produced at MIT’s Lincoln Labs, but it wasn’t until recently that they have become commonplace in the commercial laser market.  As such, they are still somewhat misunderstood. In this blog, we are going to take some time and explain their functionality and why they are so uniquely suited as compact pulsed laser sources at a wide variety of laser wa… Read More

ER: Glass Lasers for LIBS in Harsh Environments

Laser-induced breakdown spectroscopy (LIBS) is one of the most popular laser based atomic spectroscopy techniques on the market today.  Nowadays, LIBS is rapidly becoming an indispensable tool for elemental analysis and is generally viewed as a complementary technique to other elemental methods such as mass spectrometry.  LIBS has been deployed in a wide range of industrial and scientific applications including on the surface of Mars, where over 200,000 LIBS spectra have been collected aboard of the Mars Science Laboratory Rover … Read More

Flow Cytometry Review

Flow cytometry is a method for simultaneously analyzing multiple physical properties of an individual cell as it flows through a beam of light in a fluid stream, including the cells size and fluorescence.   In practice, flow cytometry is essentially a combination of particle counting and fluorescence spectroscopy.  Since we have written about both of these subjects in depth in the past, this blog will not spend very much time on the fundamentals of these two technologies instead you are recommended to read our previous blog post on Optical Particle Counting and our white paper on  Multi-Color Flu… Read More

Laser Diode Bar Stress

In this application note, we plan to combine these two topics and look at one of the key factors that affects laser diode bar lifetime – stress and strains.  Despite the extreme power output of laser diode bars and stacks, which can exceed 2 kilowatts of power in quasi continuous wave (QCW) operation, the facet coating technology has improved to the point where it can handle intensities well over 20MW/cm2 making catastrophic optical damage (COD) no longer a limiti… Read More

Laser Diode Fundamentals: Single Longitudinal Mode Diodes

In the last installment of our Laser Diode Fundamentals series, we took a deep dive into the underlying physical properties behind the longitudinal mode structure of laser diodes.  In that blog post, we explained the advantages and disadvantages to both multi-longitudinal mode and single longitudinal mode diode lasers.  We are going to expand on what we learned about single longitudinal mode diodes lasers and take a look at a wide range of stabilization techniques which are used to ensure that a laser maintains single mode performance during its … Read More

Er-YAG 2.94 Micron

Flashlamp pumped pulsed Er:YAG lasers have been widely utilized in dermatology and dentistry as an alternative to CO2 lasers, but historically continuous wave (CW) and quasi-continuous wave (QCW) Er:YAG lasers were problematic due to their unique energy level decay times.   Our friends over at Sheaumann Laser have worked hard over the years to figure out a methodology for overcoming these issues and have since developed a diode-pumped 2.94 micron Er:YAG lasers known as the MirPac series, with a maximum output power of … Read More

Using Lasers to Detect Greenhouse Gasses

Being produced in nature through the anaerobic decomposition of organic matter trapped beneath the sedimentary layers of the earth, it is found abundantly near other fossil fuels such as in coal mines.  Even though it is the simplest of all the hydrocarbons, methane gas is used widely in industrial applications such as power generation, transportation, and industrial chemical manufacturing, in addition to its more commonly known use as a consumer fuel source…. Read More

Diodes for Optical Tweezers

Micromanipulation of sub-millimeter objects is one of the more underappreciated technical challenges in modern scientific research.   To fully understand their properties, objects such as dielectric spheres, viruses, bacteria, living cells, organelles, small metal particles, and even strands of DNA all require precise positioning under a microscope even though they can often only be tens of nanometers in size.  Since these objects are too small to manipulate with a pair of tweezers, a non-contact method needs to be used to trap and then manipulate these … Read More

Laser Texturing

Injection molding is a widely used process for rapidly mass-producing low cost highly uniform mechanical parts.  On a cursory level, it is a relatively straight forward process by which molten material (metal, glass, polymer, etc.) is injected into a hollowed-out cavity, cooled down to solidify, and then ejected.  This results in the material being permanently shaped to the internal cavity of the mold.  This process has been around for hundreds if not thousands of years with the original molds being made out of clay and then broken apart to reveal the fini… Read More

Diodes for 3D Printing

Additive manufacturing, or as its more commonly referred – 3D printing, has revolutionized manufacturing processes over the past ten years.  This technology which was once reserved for high-end research and prototyping applications is now so commonplace that many elementary and middle schools through the US are utilizing them as part of their STEM curriculums. Regardless of cost or complexity, all additive manufacturing processes consist of four primary stages: 3D modeling, digital data processing, 3D object construction, and post-p… Read More

Lasers For Tattoo Removal

Nearly one-third of all Americans have at least one tattoo, and of those who do roughly one-quarter of them say they regret getting it.  As a result, nearly 27 million people in the United States alone have at least one unwanted tattoo.   Based on these numbers it is easy to see why the world-wide tattoo removal market exceeded 11.6 billion dollars in 2016.  The vast majority of these procedures are done using laser-based tattoo removal treatments because they result in the least amount of sc… Read More

First Ever Image of a Black Hole in the Center of the M87 Galaxy.

On April 10th, the scientific community was elated at the release of the first-ever image of a black hole in the center of the M87 galaxy in the Virgo Cluster.  By Imaging the photon ring around the black hole shadow and utilizing the Schwarzschild Radius, scientists were able to not only validate the existence of black holes which were predicted by Einstein’s General Theory of Relativity they were also able to accurately measure the mass of the black hole at 6.5 billion times that o… Read More

Digital Holographic Microscopy

Holography is simultaneously one of the most well-known and yet most misunderstood optical techniques.  The word hologram derives from the combination of two different Greek words “holo” meaning “whole” and “gram” meaning “drawing.”  Understanding the origin of the word itself helps to illustrate that a hologram is not just simply a three-dimensional photograph, but instead, it is a recording of “the whole” wavefront reflected or transmitted by an object including both its amplitude … Read More

Optical Particle Counting

Optical particle counting is widely deployed in cleanrooms around the world as a means for counting and sizing the number of particles in the air.  Most people who have ever worked in a clean room, are familiar with the Federal Standard 209E cleanroom classifications, such as class 10,000, class 1,000, or class 100, with the lower the number corresponding to the cleaner the room.  Where many people have misconceptions is that the classifications are not solely determined by the number of particles in the air but also t… Read More

Diodes for Acne Treatment

According to the American Association of Dermatology (AAD), acne is the most common skin condition in the United States, affecting up to 50 million Americans annually with a nontrivial percentage suffering from a chronic form of the condition. Fortunately, for people suffering from persi… Read More

Laser Diode Fundamentals: Understanding Longitudinal Modes

There are two critical parameters that all lasers diodes must meet to begin the lasing process.  The first one of these parameters is that there must be more gain than loss inside the laser cavity, the point at which this condition is satisfied is known as the gain threshold and was covered in the last installment in our Laser Diode Fundamentals series.   The second condition that must be met, is that there must be a longitudinal mode present inside the optical cavity which coincides with the laser’s g… Read More

New White Paper: Single frequency fiber lasers for Doppler Lidar

RPMC is excited to announce our most recent white paper titled “Single Frequency Fiber Lasers for Doppler Lidar.” Doppler lidar takes advantage of the fact that when light interacts with moving object, it experiences a frequency shift. This frequency shift allows you to measure the veloci… Read More

What Laser to use for TOF-MS

Mass spectrometry is an extremely powerful analytical tool for chemical analysis, which is widely utilized in applications ranging from forensics to pharmaceuticals, because of its ability to detect the atomic constituents of an analyte but also determine their relative concentrations.  This process is facilitated by ionizing the sample and then passing it through both an electric and a magnetic field causing them to spread out based upon their at… Read More

Understanding Laser Diode Lifetime

In October of 2017 RPMC Lasers, published a white paper titled “How to Improve Laser Diode Lifetime! Advice and Precautions on Mounting,” where we went on to describe in great detail the various package types and the best practices for ensuring the laser diode are appropriately heat sunk. In light of extreme interest in this topic, we have decided to expand on this topic with this application note by discussing how electrical, electro-mechanical, environmental, and optical properties also affect the diode … Read More

QCW Laser Diode Stacks: The Perfect Solution For Hair Removal Systems

According to Grand View Research, laser hair removal is one of the most popular medical laser applications worldwide and is projected to reach 2.8 billion dollars annually by 2028. Laser hair removal became popular so quickly that by 2005 Alexandrite (the laser of choice at the time) was the second most popular laser crystal grown worldwide, even though there were no other mainstream applications for Alexandrite laser technology. As of 2020, laser diodes held the lion’s share of the market (over 39%), due to their high precision, efficiency, small footprint, and relatively… Read More

The Influence of Laser Wavelength on Raman Spectroscopy

As discussed in previous posts, Raman spectroscopy is a rapidly growing analytical technique used in a wide variety of industries for material identification, but with so many different laser options it can be somewhat challenging to understand which laser is best for which application. To help elevate some of the confusion around this issue, we released an application note this past August titled “Multi-Mode vs. Single-Mode Lasers for Raman Spectr… Read More