Fiber Optic Beam Delivery

Fiber Optic Beam Delivery Systems

The U.S. Laser Fiber Optic Beam Delivery System provides the means to deliver the output of a laser system to a remote location through a flexible fiber optic cable. Fiber optic beam delivery is a convenient solution to delivering the laser beam over long distances, or where direct line-of-sight (required by conventional delivery systems) is unavailable or undesirable. The Fiber Optic Beam Delivery system is a complete package, consisting of input coupling optics mounted on an adjustable mount, a connectorized armor jacketed fiber cable, and the output coupling optics, which collimates and focuses the beam. By providing a range of fiber types and core diameters, as well as a full range of input and output coupling optics, the system can be custom tailored to almost any laser application. Individual components of the system are described below.

Input Coupler

The input coupler mount assembly positions the fiber, and focuses the laser beam into the fiber. An appropriate multi-element (or single element, if appropriate) lens, is used to focus the laser beam to a spot diameter small enough to fully couple the beam into the fiber core. The lens is mounted in a three axis adjustable mount, which provides X /Y adjustment of the fiber, and a Z axis lens focus. A bulkhead connector is provided for easy mounting and de-mounting of the fiber. Standard connectors are either D-80 or SMA, with other connectors available as options. The carriage mount is drilled for use with right or left beam entry.  On some systems, an upcollimator (see Model No. N1004) may be required in conjunction with the input coupler lens to achieve the spot size required to properly couple the beam into the fiber.  Consult the U.S. Laser sales department for assistance in selecting the correct optics for your application.

Fiber Optic Cables

U.S. Laser offers a line of high quality multi-mode fiber optic cable assemblies. Two type are available, the step index, featuring a pure fused silica core, and the gradient index, which has a doped fused silica core. Core diameters from 200 µm to 1000 µm are available in both types. Each cable is supplied as an assembly, with plastic coated armor jacketing, and D-80 or SMA connectors on both ends. Nominal numerical aperture is .2 for the step index, and .25 for the gradient index. For fibers in lengths up to ~ 20 meters, the fiber is effectively loss less, except for approximately 8% Fresnel loss at the end faces. When used with CW lasers operating in excess of 200 watts, U.S. Laser highly recommends the optional A/R coating. Special fiber sizes, connectors, and jacketing configurations are also available, please consult sales dept.

Related Products: Optical Fiber Repair Services

Output Coupler

The output coupler is a multi-element assembly which first collimates the diverging beam from the fiber output ( the output collimator section), and then re-focuses it to form an image of the fiber core (the output objective assembly). A connector is provided on the collimator assembly for easy attachment of the fiber. The lenses are mounted in precision machined in-line housings, and are pre-aligned to the fiber. The standard connector is a D-80 bulkhead, with SMA and other connectors also available. The lenses are mounted in precision machined in-line housings, and are pre-aligned to the fiber. The collimator and objective lens housings are threaded together, and may easily be removed and changed. Because the optical system is used to image the fiber core, focused spot size is easily calculated (see US fiber optic beam delivery Tech Note) and changed, if necessary.
A lens protector assembly with A/R coated glass window is available to protect the objective lens from dirt and debris.

Output Collimator Assembly

The output collimator assembly includes an A/R coated fused silica collimator lens, and housing with connector (specify D-80 or SMA).

Objective Lens Assembly

The output objective lens assembly includes an A/R coated fused silica objective lens mounted in a housing which directly couples to the output collimator housing.

Output Lens Protector

The output lens protector assembly includes a lens protector slide holder housing, which threads directly into the output objective lens housing, and an A/R coated lens protector disc.

Coaxial CCTV System

The fiber optic CCTV package is a complete in-line CCTV system designed to provide a visual image of the laser processing work area. The package includes a CCTV camera, monitor and cables, and all necessary optics. The mechanical housing threads directly into the output collimator section, and has a threaded section for the output objective lens to thread directly into. When using the fiber CCTV assembly, the beam is delivered to the work surface 90° from the fiber plane.

Related Products: Conventional Beam Delivery Systems

Coaxial Gas Nozzle Assembly

A gas nozzle designed for the coaxial delivery of inert gas while welding. Attaches directly to the fiber optic output objective lens housing (N3304). Supplied with 3 interchangeable nozzle standoff spacers, and 4 interchangeable orifice nozzles.

Related Products: Coaxial Gas Nozzles for Conventional Beam Delivery

Fiber Optic Multiplexers

Multiplexing systems allow splitting a single laser source into multiple beams, or switching a single laser between multiple fibers. These systems can be especially useful when a single laser can be used for multiple simultaneous or sequential uses at different locations. Lasers of power levels up to several kilowatts can either be divided into multiple equal beams, or a common beam can be switched between several available fibers. Standard configurations are available for splitting the beam into two or four equal beams, as well as timeshare modules to switch the beam between up to four fibers. Special configurations are available based on the number and type of outputs, the length and type of fibers, and the output focusing optics desired.

Please consult the U.S. Laser sales department for further technical assistance.

Fiber Optic
 Test Fixture

The fiber optic test fixture consists of a short section of optical rail with an integral mounting post used to support the fiber optic output collimator. The mounting post is positioned at the correct optical center line of U.S. Laser systems which allows convenient use of existing system power meters.

During normal power output measurements when using a fiber, the fiber end face must be positioned close to the power detector, since the beam is rapidly diverging. Using a collimator, such as what is typically supplied on U.S. Laser fiber optic beam delivery systems (Model # 3303), allows the fiber to be positioned at a safe distance from the power detector, and protects the fiber end face from being damaged due to dust or dirt.