High Power Laser Coupling, Connectorization, Beam Shaping

Silica (SiO2) optical fibers made by high-purity chemical vapor deposition processes (CVD, OVD, VAD, MOCVD) have remarkable power-carrying capacity. But “high power” is a relative term. The cross-sectional area of the energy-guiding core is the key determinant of the power-handling capacity in fibers. The larger the fiber, the more energy can be carried in the bulk silica.

In a “small-core” single mode fiber (core diameter of 5-15µm), “high power” might mean 1-2 watts, whereas in a 600µm core hard polymer-clad fiber (HPCF), “high power” may mean 100 watts.

A fiber laser may output a kilowatt or more from a doped, double-clad fiber – even out to IR wavelengths at 10.6µm. 

Several design goals are common to all coupling, guidance, connecting and beam-shaping endeavors when high power is involved: Laser sources with well-controlled beams; highly-polished input fiber facets with no defects; low attenuation at the operating wavelength; connectors and fiber-guiding mechanisms appropriate for the optical power levels.

Selecting a fiber with the right core, clad, and numerical aperture (NA); correct glass composition – pure or doped; coating and buffer materials are all important, but only the starting point. 

  • Berkshire Strengths:
    • Fiber and laser input beam matching
    • Core size and NA selection; cladding thickness and coating design
    • All-silica vs. hard plastic clad fibers vs. double-clad fibers
    • Optical bend radius vs. mechanical bend radius
    • Epoxy-polish vs. no epoxy connectors
    • Cleave vs. polish
    • Air-gap vs. end-cap terminations
    • High power fiber to fiber connections


Whether the output beam needs to be focused, expanded, collimated, or diffused, Berkshire has the experience and capability to realize your design.

  • Berkshire Solutions:
    • Finding the multi-dimensional “sweet spot” in the tradeoffs between – core diameter and spot size
    • Laser beam quality (“BQ”) and fiber NA
    • Connector design vs. damage resistance
    • Damage resistance vs. fiber cost


Berkshire can help you find the perfect combination of glass type, fiber design, coating materials, end-finish and termination approach that achieves the delivered power, safety, reliability, and lifetime required by your application. 

Whether for precision, low loss and back reflection epoxy-polish terminations or specialized air gap or end-cap solutions, Berkshire has the metrology and inspection capabilities to assure performance on single mode, mid-core and large core fiber and bundle assemblies.  


  • Product Focus:
    • High power laser delivery cables from UV to visible to NIR and IR (λ= 200nm to 10µm)
    • Mid-power bundles, splitters combiners and arrays
    • Single mode high power cables for DTS and other intrinsic fiber sensors
    • Mid-power multi-wavelength spectroscopy assemblies
    • High temperature fibers/cables for laser delivery
    • Laser power diffusers for PDT and similar laser light diffusion applications
    • High power SMA and special connectors, both epoxy, no-epoxy and end cap designs from 50µm clad reduced-diameter fibers to 3mm fiber rods to hollow core fibers.


Contact Us at 860-868-0081 to discuss your High-Power Laser Assembly requirements – whether single mode cables for distributed temperature sensing; or a 40 watt laser diode aggregation for a fiber delivered, laser light source, Berkshire Engineers Solutions


Visit Us At
Booth 3208!

CHallenge us!

Fill out the form below, and we will be in touch shortly.
Contact Information
Tell Us More About You
Tell Us About Your Challenge