Laser Diode Blog Posts

A near-diffraction-limited single-mode beam is usually the better starting point when tight focusing and spatial resolution are important, such as in high-resolution Raman microscopy. Multimode sources can be appropriate for fiber-probe, bulk-sampling, and other systems where the optical architecture can efficiently use a larger or less tightly focused beam.

But spatial mode is only one part of Raman laser selection. Excitation wavelength, spectral linewidth, wavelength stability, spectral purity, available power, power stability, beam delivery, and the sample itself can all matter jus… Read More

Shorter excitation wavelengths generally produce stronger Raman scattering, while longer wavelengths can reduce fluorescence that might otherwise overwhelm the Raman signal. That is why there is no single “best” Raman laser wavelength for every measurement.

Common Starting points include visible wavelengths such as 532 nm, near-infrared excitation around 785 nm, and 1064 nm for measurements where fluorescence remains a significant problem. Specialty applications may also benefit from UV or other excitation wa… Read More

For any laser to function, there must be more gain inside the laser cavity than loss, and the point at which the laser gain is just large enough to overcome the cavity loss enabling lasing is called gain threshold.  While simple, in theory, this concept of gain threshold can be particularly challenging to understand, particularly when it comes to diode lasers.  Therefore, as part of our ongoing blog series expanding on the topics covered in our Lasers 101 section, we are going to explore the concept of laser diode gain threshold in this … Read More

Researchers at the Laboratoire de Physique des Lasers (LPL), part of the Comomet consortium, achieved a world-record by stabilizing mirSense UniMir QCLs (10–17µm) to a relative 10⁻¹⁴ level—sub-Hz precision at 30 THz. This enables ultra-precise spectroscopy of methanol to test proton-to-electron mass ratio variations over cosmic scales, and supports studies of cold chiral molecules (enantiomers), where heavier species benefit from longer wavelengths (>10µm, ideally >15µm) for lower excitation energies and improved me… Read More

For nearly 30 years, RPMC Lasers and LDX Optronics have partnered to deliver cutting-edge laser diode solutions for the Medical Market, transforming dental systems with customized, high-power diodes. This case study showcases how our collaboration with a leading dental equipment manufacturer revolutionized soft tissue laser systems for periodontal, hygiene, and surgical applications. Explore how RPMC’s expertise and LDX’s packaging innovation can power your next project with the LDX Optronics … Read More

The Medical Laser Market is booming with a surge of aesthetics laser applications, driven by demand for non-invasive treatments like tattoo removal, hair removal, acne therapy, and various other applications. With over a century of combined expertise, RPMC Lasers partners with professionals to deliver tailored laser solutions for these applications. This article explores how advanced laser diodes and systems power these leading aesthetic treatments, guiding you to the right choice with RPMC’s cutting-edge… Read More

Acne, affecting up to 50 million Americans annually, is the most common skin condition in the U.S., often requiring persistent treatment. Short-wave infrared (SWIR) laser diodes in the 1400–1500 nm range offer a breakthrough by targeting sebaceous glands to reduce oil production, minimizing lesions with minimal side effects. For dermatology professionals and OEM integrators, selecting the right SWIR laser diode is key to delivering effective, FDA-approved acne treatments. This article explores how SWIR diodes power acne therapy and guides you in choosing the ideal solution, spotlighting RPMC Lasers’ SWIR laser diodes for precision and reliability in the Medic… Read More

For over three decades, LDX Optronics has delivered high-power multimode laser diodes, powering cutting-edge applications in Medical, Defense, and Industrial sectors. As RPMC Lasers’ exclusive North American partner, LDX offers an unmatched range of wavelengths (400–1900 nm) and power levels (up to 40 W), with industry-leading packaging expertise. This article explores LDX’s diode solutions, their applications, and how to select the right laser for your needs, spotlighting the LDX Optronics portfolio for superior pe… Read More

Laser diodes have transformed dental procedures, particularly crown troughing, by offering fast, precise, and bacteria-eliminating solutions. For dental professionals and Medical OEM integrators selecting a laser diode, understanding the requirements for crown troughing is crucial. This article briefly explains the role of laser diodes in dental applications and outlines key considerations for choosing the right infrared laser diode, highlighting RPMC Lasers’ LDX-IR-FC fiber-coupled laser diode for optimal pe… Read More

Photodynamic therapy (PDT) revolutionizes cancer treatment by using red laser diodes to activate photosensitizing drugs, offering a non-invasive alternative to surgery or radiation. For Medical & biomedical professionals and OEM integrators, selecting the right laser diode is critical for effective, targeted treatments. This article explores how red laser diodes power PDT and guides you in choosing the ideal solution, spotlighting RPMC Lasers’ LDX-VIS-FC fiber-coupled laser diode for dermal, subdermal, and endoscopic app… Read More

The global laser hair removal market is booming, projected to reach $2.8 billion by 2028, driven by demand for precise, non-invasive treatments. Laser diodes, holding over 39% market share as of 2020, lead this growth thanks to their efficiency, compact design, and cost-effectiveness. For aesthetic professionals and OEM integrators in the Medical Market, QCW (quasi-continuous-wave) laser diode stacks offer the perfect solution, outperforming traditional flashlamp-pumped systems like Alexandrite and Nd:YAG lasers. This article explores the principles of laser hair removal, why QCW stacks excel, and how to select the right system, spotlighting RPMC Lasers’ JOLD-Stacks for optimal pe… Read More

Once thought to be impossible, blue, green and UV laser diodes have now become commonplace.  These lasers are being used in a wide range of applications from blue-ray players to commercial lighting & displays to copper welding.  In this post, we are going to take a look at the underlying material properties of semiconductors, GaN in particular, and how it has led to the development of blue, green and UV las… Read More

Accurate OH measurements are a growing need in combustion research, but existing sensor architectures are challenging to make economic, compact, and robust. The need for robust OH sensors is amplified in the global effort to decarbonize combustion. Many species, such as CO and CO2, have robust, high-speed laser absorption sensors targeting their fundamental vibrational bands in the mid-infrared; however, certain species like OH do not have a favorable vibrational spectrum, complicating sensing in the mid… Read More

Mid-IR molecular spectroscopy is a rapidly developing and promising technique, enabling high-performance chemical detection and analysis for industrial or environmental purposes, with new wavelength ranges becoming commercially available. The essential component for such applications is the laser source, adapted to the specific spectral lines (the fingerprint) of the target molecule. Quantum Cascade Lasers (QCLs) are a perfectly suited solution to build such analysis… Read More

Laser diodes must meet two critical requirements to facilitate the lasing process. The first requires that, at a minimum, the laser cavity’s gain increases to the point that it reaches unity with the level of losses. This unity state is known as the gain threshold. The second requirement is that there must be a longitudinal mode present inside the optical cavity, coinciding with the laser’s gain curve. This article explores precisely what longitudinal modes are and how they affect the laser diode’s pe… Read More

When operating a laser diode, proper thermal management is critical to avoid damage. A few key aspects to consider are the generation and dissipation of waste heat, laser diode operating temperature, and proper heatsinking. This article will focus on TO-Can packages, giving consideration to these key aspects and providing useful information for proper thermal m… Read More

Whether a diode laser is a traditional monolithic design or utilizes an external cavity configuration, the laser light must still propagate through the diode’s PN-junction via a ridge waveguide.   As a result, the beam profile of edge emitting diodes is unique when compared to all laser sources because of the asymmetric geometry of this optical cavity.  This issue often leads to confusion about how to properly integrate open beam laser diodes into yo… Read More

Within the laser community, one of the most overused and often miscommunicated terms is the phrase “single mode.”  This is because a laser beam when traveling through air takes up a three-dimensional volume in space similar to that of a cylinder; and just as with a cylinder, a laser beam can be divided into independent coordinates each with their own mode structure.  For a cylinder we would call these the length and the cross-section, but as shown in the figure below for a laser beam, we define these as the transverse electromagnetic (TEM) plane and the longitud… Read More

For many years, space applications have steadily increased the utilization of laser diodes for various instruments (mainly pump sources for solid-state lasers). Because of this, organizations have developed qualification methodologies to ensure high levels of quality, performance, and lifetime. In recent years, increasingly complex scientific payloads have required more precise lasers for metrology, calibration, and environmenta… Read More

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

RPMC Lasers is proud to announce that two of our esteemed partners, Seminex Corporation and Spectrolight, Inc., have been honored with the 2024 Innovators Awards from Laser Focus World. This prestigious recognition highlights their exceptional contributions to the photonics industry and underscores their commitment to innovation and exc… Read More

Raman Spectroscopy has become increasingly popular in recent years. With more demand for this application, some companies have strived to make advancements to the associated technology and hardware, in an effort to provide better results, more throughput, increased flexibility, and a reduction in total footprint of these devices. This Raman Probe provides great flexibility with configurable optics and advanced features like dual-wavelength capability using only one spe… Read More

Micro-welding is a high-precision welding method employed to fuse minuscule metal parts or features together. Traditionally, this requires a highly skilled specialist, utilizing a variety of skill sets and knowledge of various materials’ properties, taking into account all of the particular considerations involved in such a precise, delicate process. The Ford company first developed micro-welding to solve the problem of welding materials in a vacuum tube with a high melt… Read More

Single-frequency lasers have long been the cornerstone of standoff gas detection applications, particularly in traditional LIDAR (Light Detection And Ranging), DIAL (Differential Absorption LIDAR), and TDLAS (Tunable Diode Laser Absorption Spectroscopy) applications, where the sample needs to be accurately measured.  More recently, as single-frequency laser diodes have become more common and less expensive, with a larger measurement range and compact size, they are being utilized in more localized and industrial gas sensing app… Read More

Driving a vehicle at night or during foggy conditions can be tricky and dangerous, where poor visibility can cause undue stress or even an accident. These conditions make it more difficult to see upcoming potential obstacles, especially if that obstacle is a deer in a field or a pedestrian in dark clothing at night. However, thanks to newer, more efficient, and cost-effective advancements, we could see more widespread deployment of LIDAR-based automotive detection and warning… Read More