Regarding fiber optics or optical fibers, polarization-maintaining optical fiber (PM fiber or PMF) is referred to as a single-mode optical fiber that maintains the linear polarization of light during propagation down the fiber, if the polarized light is properly coupled into the fiber.
This light then exits the end of the fiber in a particular linear polarization state, and there is no (or very little) cross-coupling of optical power between the two modes of polarization. PM fibers’ principal operation relies on a systematic linear birefringence within the fiber. This defines two polarization modes along the length of the fiber with two unique phase velocities. This type of fiber is critical when attempting to deliver polarized light through a fiber optic cable for an application requiring the polarization to be preserved at the target.
In a typical, non-polarization-maintaining fiber, the circular symmetry allows both vertical and horizontal polarization modes to have the same phase velocity. Some birefringence is still present in these fibers, however. These bits of birefringence and even bends in the fiber can cause crosstalk between these two polarization modes. Even in a very short length of optical fiber, this crosstalk can lead to a power transfer from one polarization mode to another, effectively changing the polarization. This typically leads to a sort of random polarization, as the polarization will vary with changes in bends, other stresses, and wavelength.
Our Polarization-Maintaining Fiber Products
RPMC Lasers is your Polarization-Maintaining Fiber Laser supplier! We offer a wide range of PM fiber output lasers, including Laser Diode Modules, CW DPSS Lasers, CW Fiber Lasers, Multi-Wavelength Beam Combiners, Single-Emitter Laser Diodes, Distributed Feedback (DFB) Lasers, Volume Bragg Grating (VBG) Laser Diodes, and Superluminescent Laser Diodes (SLEDs or SLDs). Among these options, we provide many wavelengths from the UV to the SWIR spectral regions, many power options up to 10s of Watts, and narrow linewidth output options.
Deeper Dive into PM Fiber Output Lasers
Multimode vs Single-Mode Lasers for Raman Spectroscopy
The final and perhaps least obvious consideration is the samples crystallinity. Crystallinity is a measure of how structured the atoms of molecules in a solid are ordered. This is important because like all nonlinear effects, Raman scattering is polarization dependent, and if the sample is highly crystalline then the orientation of the sample relative to the laser’s polarization will affect the resultant Raman spectrum. While always present, this effect is not noticeable in amorphous samples, because the random orientation of the atoms and molecules in the samples causes these variations to be averaged out. Similarly, if the laser is randomly polarized then, the same averaging effect takes place, only by the laser’s random polarization as opposed to the samples random orientation. For this reason, when analyzing crystalline materials, it is necessary to first ask the question, “Am I looking to analyze the crystalline structure, or identify the material?” If the goal of your application is to study the crystalline structure, then single-mode lasers are generally preferable, due to the high polarization extension ratio. On the contrary, if your goal is to repeatedly identify the material (for example is this crystal methamphetamine or rock candy), then a fiber-coupled multi-mode diode laser would be the best option due to its highly random polarization.
HeNe Lasers vs Diode Lasers: HeNe Laser Pros and Cons
Despite of so many good intrinsic properties, HeNe lasers often do not meet the requirements of today’s industrial environments. Industrial production lines with 24/7 operation are all about robustness and long lifetime, thus industrial instrument manufacturers tend to pay 2 to 4 times more for a laser, which has a longer life-time, is easier to replace and maintain.
The price difference from HeNe lasers mainly depend on how many parameters of semiconductor lasers have to be close to the performance of HeNe. If one needs perfect beam quality, single-mode or polarization maintaining fiber has to be used to achieve <1.05 M2, nice round beam shape and diffraction limited divergence. Reasonably good central wavelength stability can by achieved by good temperature and power stabilization of the semiconductor emitter. Most difficult and expensive to achieve is the long coherence length requirement. Most popular way of ensuring high coherence length and very stable (<5 pm) central wavelength is to apply external cavity designs (ECDL – external cavity diode laser) by using volume Bragg gratings or fiber Bragg gratings.
With over 25 years experience providing many types of laser diodes with various fiber-coupled output configurations to OEM integrators working in different markets and applications, and 1000s of units fielded, we have the experience to ensure you get the right product for the application. Working with RPMC ensures you are getting trusted advice from our knowledgeable and technical staff on a wide range of laser products. RPMC and our manufacturers are willing and able to provide custom solutions for your unique application.
If you have any questions, or if you would like some assistance please Contact Us here. Furthermore, you can email us at [email protected]to talk to a knowledgeable Product Manager.
Alternatively, use the filters on this page to assist in narrowing down the selection of PM Fiber lasers for sale. Finally, head to our Knowledge Center with our Lasers 101 page and Blogs, Whitepapers, and FAQ pages for further, in-depth reading.
The FL CW/CW Modulated Series offers a variety of standard and custom CW fiber laser options. Available in both OEM and Turnkey formats, our 1um, 1.5um and 2um fiber lasers are manufactured to Telcordia standards and can be modified to meet your applications requirements. With available powers up to 100W at 1um, 30W at 1.5um and 40W at 2um, our CW fiber lasers are suitable for a wide range of applications. Available options and configurations include narrow linewidth, single frequency outputs, C and L-band broadband sources, PM fiber options, power tunability and high-speed trig./mod. Customized configurations are available upon request.
The Matchbox series offers excellent performance and reliability in the “World’s Smallest” ultra-compact, all-in-one, integrated laser head. They can operate on a 5V power supply while maintaining low noise operation. The monolithic design of the Matchbox Series laser includes thermally stabilized optics in a hermetically sealed housing, ensuring reliable and maintenance-free operation. This series is available in wavelengths from 405 nm thru 1064nm, with options for collimated beam or fiber-coupled output, and single-mode and multimode versions.
The LaserBoxx Low Noise series of CW diode laser modules, with a variety of wavelengths from 375 to 785nm and output powers up to 350mW,offers highly customizable laser solutions for OEM and plug & play modules. With advanced features such as excellent beam quality, stability, and modulation capabilities, our lasers provide ultra-low noise and a wide range of options for SM, MM, and PM fiber coupling. Our dedicated control software, USB and RS232 interfaces, and external controller with power display make integration, operation, and remote diagnostics a breeze. Additionally, our rugged and compact design and wide variety of standard wavelengths ensure that our lasers can meet your specific needs.
The LaserBoxx-SLM series are single longitudinal mode (SLM) CW diode laser modules available in green, yellow, red, and NIR wavelengths, delivering ultra-narrow linewidths, with excellent temperature stability and low noise current. Embedded firmware locks the laser on the same mode at each startup. This customizable, compact, self-contained laser module is available in turn-key or OEM versions and utilizes a proprietary alignment-free, monolithic resonator, and comes standard with a graphic user interface with remote diagnostics via USB, RS232, or direct I/O interface. With modulation capabilities and adjustable power options, the SLM Series is versatile and adaptable to a wide range of applications.
The LXCc series is a range of compact, highly customizable, and flexible all-in-one laser combiners that provide the widest variety of wavelength options, up to 7 different laser lines (up to 500 mW output power per line), direct modulation on every source, SLM capabilities, proven long-term stability, and many other advanced features. The turnkey or OEM versions allow a large choice of lasers from 375nm up to 1064nm. The extension module provides the ultimate level of flexibility with options for up to 4 optical fiber outputs, AOTF modulator, motorized ND filter, integrated fast switching output ports for FRAP, or adjustable split power for light-sheet microscopy.
The R series of wavelength stabilized single–mode and multimode laser diodes offer narrow linewidth output in wavelengths from 633nm thru 1064nm. This highly customizable series offers package options ranging from components as basic as a TO-56 or 14-pin BF packaged diodes, to OEM modules including electronics, to UL/CE and IEC certified turn-key systems. The R series is the perfect source for various markets, including chemical analysis, bio-medical, fiber laser, and scientific applications.
The REP series includes high-performance, tunable, single-frequency (DFB-like) diode lasers and Fabry-Perot laser diodes in wavelengths from 1270nm thru 2350nm, designed to address challenges in Gas Sensing, LIDAR, Spectroscopy, and Telecom. The REP series includes high-power and narrow linewidth options, covering various product ranges at the most popular wavelengths, providing customizable units with multiple packaging options, including the Fiber coupled 14-pin butterfly, TO39 (w/TEC), and TO56. For a complete module incorporating the fiber-coupled butterfly package with an integrated current driver and TEC controller, designed for ease of operation, it is the ideal platform for high stability gas detection or remote sensing. See the DX1 Series.
The RWLP series offers an affordable and versatile solution for your laser application needs with single-mode and multimode options and wavelengths from 405nm thru the IR region. With customizable options, our team can work with you to solve any challenges you may face. Rigorously tested for long-term reliability, the RWLP series ensures consistent performance and high beam quality. Perfect for integration, this series supports multiple applications including biological and analytical instrumentation.