RPMC Lasers Blog

It is well known that the output beam characteristic of a multimode laser diode is inherently non-uniform, due to both spatial and temporal variations of the mode profile, that result from thermal lensing and filamentation. These non-uniformities (‘hot-spots’ and ‘dark-spots’) can lead to deleterious effects for many applications, including solid-state laser pumping, Raman spectroscopy of sensitive materials, laser speckle contrast imaging, and laser ill… Read More

LiDAR is a critical component of ADAS (Advanced Driving Assisting System), AVs (Autonomous Vehicles), and industrial automation systems. Highly efficient VCSELs (vertical-cavity surface-emitting lasers), with their tiny footprint, attractive pricing, and remarkable reliability and performance, will undoubtedly have an increased positive effect on the LiDAR industry. 100% solid-state LiDAR systems show great potential as the next evolution in LiDAR technology, aiming to replace traditional bulky and expensive mechanical spinning and microelectromechanical systems LiDA… Read More

Integrated Optics, UAB has recently upgraded the World’s smallest 4-wavelength laser combiner. This new release is widely configurable and has a large selection of wavelengths and output types. A redesigned Break-out-Box (BoB) accessory provides more functionality and durability when used in scientific setups. SM and PM fiber coupling, with more than 50% fiber coupling efficiency, is finally available as well. You can select a maximum of 4 wavelengths from 405nm, 450nm, 488nm, 520nm, 638nm, 660nm, 785nm, 830nm, 850nm, 975nm, 1064nm. Further extensions into the infrared are in consideration for de… Read More

A common problem for HeNe laser customers is the issue of polarization switching, which is the sudden change of the polarization of different modes, especially in shorter tubes, which can be particularly detrimental when operating frequency stabilized HeNe laser tubes. This phenomenon is sometimes referred to as ‘mode hopping.’ However, this is not accurate. While somewhat similar to polarization switching, mode hopping involves the laser’s operation on a single resonator mode, which suddenly switches to another mode, causing the optical power to switch over to this… Read More

In this blog, the concept of “Raman Concatenation” is explained as a measurement technique utilized to overcome many of the previously outlined trade-offs. In general, many Raman measurements suffer from fluorescence, which forces the use of longer excitation wavelength (lower photon energy) lasers to prevent the fluorescence signal from overwhelming the Raman signal. However, this results in reduced sensitivity of low-cost silicon CCD detectors at higher wavenumbers, making it difficult (or impossible) to observe the “stretch” portion of the Raman spectra (i.e. 2000 – 4… Read More

Shortly after the invention of the first laser, a relevant application enabled by the availability of coherent light, called time-of-flight, emerged. ToF is the precise measurement of the round-trip time of a laser pulse from the source to the target object and back again, allowing you to determine the distance or the velocity of the target. By collecting the back-reflected (or back-scattered) radiation of a short pulse, initially directed to a remote target, it is possible to determine the exact position of said target, provided that the time interval between the outgoing pulse and the corresponding echo is precisely… 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).  More recently, as single-frequency laser diodes have become more common and less expensive, they are being utilized in more localized and industrial gas sensing app… Read More

For security purposes, ID cards often require some form of unique identifier and tamper-proof security features, designed to mitigate the potential for alteration and counterfeiting. Laser sources play an essential role in this regard, providing a means to create permanent, high-quality, and tamper-proof marks on polymeric cards. Typically, the ID cards are a multi-layer composition of poly-carbonate and PVC, with select pigments added to the inner layers of the card during fa… Read More

Jenoptik is now offering the JOLD-275-CPNN-1L, their latest development in the field of high-power laser sources for industrial material processing, medical, and life science applications. Thanks to Jenoptik’s patented mounting and bonding technology, this new, passively cooled diode laser is able to achieve extremely high performance in hard pulse and CW applications. Jenoptik also utilizes the efficient and high-performance semiconductor materials they produce themselves to manufacture their high-power las… Read More

we will highlight another set of lasers offered here at RPMC, which are ideal for higher-order harmonic generation, allowing it to produce wavelengths from the infrared to the ultraviolet; the Sol, Wedge, and Onda from Bright Solutions.  All three of these laser sources are robust and compact, making them ideal for integration into OEM systems.  In this blog, we will highlight several of the features which make each unit uniquely suited for harmonic c… Read More

Diode lasers come in a wide variety of packaging configurations. Each package type provides different pros and cons when it comes to beam delivery, heat sinking, integration, and so on.  The two most common packages for what we call “component level” diode lasers are the TO-can and the 14-pin butterfly package.  While there are some exceptions, in general, the TO-can is the preferred packaging for open beam laser delivery, and the butterfly is preferred for fiber-coupled beam d… Read More

Having trouble deciding which fiber-coupling connection is best for you? Check out our newest white paper, titled “Choosing the Right Connector for Your Fiber-Coupled Laser Diode.”  In this paper, we review: Pros and cons of the most common fiber optic connectors and the Importance of the self-centeri… Read More

Solid-state lasers offer many advantages over other laser sources. One of their most unique benefits is the ability to produce extremely high pulse energy.  Solid-state lasers can achieve this through q-switching, which is a process where the resonator losses are periodically increased, therefore interrupting the lasing process.  Unlike other laser pulsing methodologies, q-switching is unique in that the pump source remains active while no lasing is oc… Read More

When you look through a window at night and see your reflection, that is because on average 4% of the incident light is reflected at the interface between air and glass.   While 4% may seem like a small amount when dealing with lasers, a 4% back reflection can have more than enough power to destabilize or even permanently destroy the laser.    If the laser beam is perfectly aligned through the system, so too will the back reflections be perfectly aligned to go back into the las… Read More

Electric power is determined by the product of the voltage and current supplied to a device. As a result, when designing an adjustable power supply, one of those two parameters must be variable, and the other constant if you want to be able to tune the power supply to your desired output. These two types of supplies are known broadly as constant current (CC) and constant voltage (CV) output circuits. When driving a laser diode, both CC and CV power supplies have pros and cons, but the rule of thumb is that you should always use a CC supply and never… Read More

Ever since the industrial fiber laser boom in the early 2000’s, there has been an ongoing debate about the most efficient way to produce high power, fiber-coupled, diode pump lasers. At its root, this debate comes down to the question of single-emitters versus diode bars. While single-emitters cannot come close to the power levels produced by diode bars, typically only producing a few watts of output power, they have several advantages over bars that make them far more desirable for systems in… Read More

Thanks to the experience Bright Solutions has acquired in the state-of-the-art design of sub-ns DPSS lasers over the years, the Wedge family has recently been updated in terms of performance and available models. These improvements include increased average output power, and improved pulse energy stability, while maintaining a sub-ns pulse width and the ability to optimize laser performance at higher repetition rates. They also boast high peak output powers, with relatively low energy and heat generation, as well as myriad of customization possibilities and options to tweak and enhance yo… Read More

In part one of this blog series, we set out to answer the question of “how to get the right laser spot at the right distance?”  As we went on to explain, this simple question doesn’t have a simple answer, especially when we are talking about single-mode fiber optics.  In that post, we took the time to go through
an introduction of Gaussian beam optics and provided a few examples of how that can be used to determine the lens you need to choose for a given spot size.  In part two, we are going to explore the far more straightforward case of imaging a multi-mode las… Read More

At RPMC, we are excited to announce the release of our newest white paper titled “Laser Requirements for Time Gated Active Night Vision Imaging Systems.”  In this paper, we review the fundamentals of modern night vision camera technology. We then go on to discuss the differences between active and passive imaging systems.  Finally, we will explore the advantages and disadvantages of using laser-based, active imaging systems and illuminating why, in some instances, lasers are the preferred illumination source, despite their inherent … Read More

RPMC is proud to announce the release of their new Homogenized Multi-Mode 14-Pin BF Diode.  This multi-mode, wavelength stabilized laser features high output power with low power consumption and narrow spectral bandwidth. Another exciting feature is the shaped and homogenized beam profile, which evenly spreads out the power density and shapes the beam to match the field of view of a camera. The Homogenized Multi-Mode 14-Pin BF Diode is designed to replace expensive DFB, DBR, fiber, and external cavi… Read More

Perhaps the most common question we get here at RPMC, is how to get a specific laser spot size at a given distance.  This seemingly simple question of “which lens should I use?” or “how to get the right laser spot at the right distance?” is actually a rather complex problem that is highly dependent on the particular type of fi… Read More

For people without a background in electrical engineering, understanding the finer details of analog and digital modulation can be quite challenging.  This is compounded by the fact that most texts on the subject already assume that the reader has a working knowledge of linear systems and Fourier analysis, which can be a significant obstacle for most. Therefore, it is no wonder that one of the most frequently asked questions we get here at RPMC, is “should I use analog or digital modu… Read More

Approximately half of the laser diodes that we provide here at RPMC Lasers are fiber-coupled.  For this reason, we have decided to build upon our recent two-part blog on fiber coupling in our Laser Diode Fundamentals series by exploring the differences between pigtailed laser diodes and fiber-coupled laser diodes.  To understand the differences, first, it is helpful for us to review core diameter, which is an important principle discussed in the first part of our fiber coupling series. When thinking about a fiber’s core, it is useful to separate them into two different categories single-mode and … Read More

As most people already understand, a laser diodes performance is highly dependent on its operating temperature, which is why most mid- to high-end laser packages utilize embedded thermoelectric coolers (TECs).  The strong temperature dependence arises from two fundamental properties of the diode itself.  First, as the temperature of the semiconductor varies, it’s gain band shifts up or down, this is known as redshifting and blu… Read More

Over the past year, we here at RPMC Lasers have published several different pieces of technical content on various LIDAR applications.  Some of our more recent posts include a white paper titled “Single Frequency Fiber Lasers for Doppler LIDAR,” and a blog post on the use of aerial LIDAR in bathymetry.  LIDAR is quickly becoming one of the most rapidly growing sectors of the overall laser market.  In fact, Market Insider recently reported that “ The market for LIDAR is expected to grow double in size in the next five… Read More