Linear-to-Linear Fiber Optic Bundles

Linear-to-Linear Fiber Optic Bundles

• Multimode Fiber Bundles with Low-OH or High-OH Fiber
• Linear-to-Linear Coherently Mapped Configuration
• Optimized for Use with Spectrometers with an Entrance Slit

Linear-to-Linear Fiber Optic Bundles

  These fiber bundles contain 7 fibers arranged in a line configuration (linear) at both ends. Linear-to-linear fiber bundle cables are ideal for increasing the coupling efficiency into spectrometers and other optical devices that have an entrance slit. The linear ends match the shape of the entrance slit better than a single fiber or round bundle configuration and therefore increase the amount of light entering the device. The linear ends are also better suited to the elliptical emissions of typical discharge style lamps and measurements using cuvettes, such as absorption spectroscopy.

  These linear-to-linear fiber bundles use SMA905 connectors for compatibility with most spectrometers. They are built using our Ø105 µm or Ø200 µm core multimode fiber with either a high or a low hydroxyl ion (OH) content for use in the 250 - 1200 nm or 400 - 2400 nm range, respectively. For increased durability, these cables incorporate stainless steel protective tubing (FT05SS).

  • Features

  • Linear-to-Linear Fiber Bundles with 7 Fibers
  • Low- or High-OH, Ø105 µm or Ø200 µm Core Multimode Fiber
  • 2m Long Cables with SMA905 Connectors
  • Coherently Mapped Configuration
  • Linear Ends Match the Entrance Slit of a Spectrometer for Higher Signal Levels
  • Linear Ends can Generate a Line Illumination Pattern
Linear Bundle End                    

         End Face of a BFL105HS02 Fiber Bundle 
        Behind the 20 µm x 2 mm Entrance Slit of a 350-700nm Compact Spectrometer 
  • Specification

Item #





Number of Fibers


Fiber Core Size

Ø105 µm

Ø200 µm

Linear End Fiber

0.90 mm x 0.13 mm

1.55 mm x 0.23 mm

Round End Effective
Core Diameter

355 µm

640 µm

Fiber NA


Hydroxyl Ion Content

High OH

Low OH

High OH

Low OH

Wavelength Range

250 - 1200 nm

400 - 2400 nm

250 - 1200 nm

400 - 2400 nm

Fiber Attenuation Plot  


2 +0.075/-0 m



  • The NA of the bundle is the same as that of the individual fibers.
  • Notice
When plugging the linear end of the bundle cable into the spectrometer or another device, the fiber array must be aligned with the entrance slit. For ease of alignment, the fiber array's axis is indicated by a line on the connector sleeve, as shown in the image below. Precise alignment of the bundle and slit is not critical, but misalignment of more than ±5° can cause a reduction in signal strength. In order to maximize signal intensity, we recommend rotating the bundle while monitoring light levels in the spectrometer; once optimized, tighten down the threaded portion of the SMA connector to lock the bundle in place. When using these bundles with our CCD Spectrometers, the fiber array should be oriented vertically.

An Engraved Mark on the Connector's Strain Relief Sleeve Indicates the Axis of the Linear Fiber Array

Each patch cable includes two rubber and two metal protective caps that shield the connector ends from dust and other hazards. Additional CAPM Rubber Fiber Caps and CAPSM Metal-Threaded Fiber Caps for SMA-terminated ends are also offered separately.

※ Note: The fibers in these bundles are coherently mapped, occurring in the same order on both ends of the bundle.

  • Application Ideas

  • Coherence of Linear-to-Linear Bundles
The fibers within these bundles are coherent. As shown in the illustration to the below, the fibers remain in the same order with respect to each other from one end of the bundle to the other, though their orientation may be reversed by rotating one end by 180º.

Linear-to-Linear Bundle Coherence
  • Benefits of Linear-to-Linear Bundles

The shape of the linear ends of these bundles matches the entrance slit of a spectrometer better than the end of a single fiber or a round bundle. Similar to the narrow entrance slit of a spectrometer, the shape of cuvettes used for absorption spectrometry is better suited to the linear ends of these bundles than to the ends of single fibers or round bundles, further increasing the efficiency of absorption spectrometry measurements. In addition to the cuvette and the entrance slits of the spectrometer, typical discharge style lamps have highly elliptical emission volumes that also couple more efficiently to linear bundle ends.

  • Absorption Spectroscopy

Spectrometers measure the properties of incident light over a specific range of the electromagnetic spectrum. When light passes through a sample containing cells or particles before reaching the spectrometer, the amount of light reaching the spectrometer will be decreased due to the absorption or scattering of light by the contents of the sample. The measurement of the percentage of light that is transmitted through the sample is called absorption spectroscopy and can be used to measure the progress of an enzymatic reaction, the concentration of a sample, or the absorption spectrum of a sample.