About Laser Speckle Patterns Exiting Multimode Optical Fibers
A speckle pattern is a spatial high-frequency random intensity pattern of energy produced by the mutual interference of a large number of coherent wavefronts. When light is transmitted in a multimode optical fiber, many modes of light exist with different optical phases. When observed at the end of the fiber, a laser speckle pattern exists as shown in Figure 1. Mode mixing will cause interference effects that alter the intensity and the form of the speckle pattern due to even very small perturbations to the fiber. The fiber is very sensitive to pressure, vibration, and motion changes.

Figure 1. Speckle pattern exiting fiber due to modal interference.
Speckle patterns are observed in the near field at multimode fiber (MMF) output facets. Figure 1 shows speckle patterns observed at the near field of a conventional MMF with a 650-nm laser.
About In-line Laser Speckle Reducer (De-Speckler, or Fiber Optical Beam Homogenizer)
In-line Laser Speckle Reducer (Fiber Optical Beam Homogenizer)
FEATURES OF LASER SPECKLE REDUCER (IN-LINE FIBER OPTICAL BEAM HOMOGENIZER)
- High Transmission Efficiency
- In-Line All-Fiber Structure
- Small and Compact Designs
- High Reliability and Stability
APPLICATIONS OF FIBER OPTICAL SPECKLE REDUCER (IN-LINE LASER BEAM HOMOGENIZER)
- Reduce Laser Speckle Noise (Hot Spots)
- Eliminate Striations and Beam Non-uniformity
- Beam Homogenizing
- Laser Material Processing
Intensity Profile of the Output Beams: WITHOUT V.S. WITH Laser Speckle Reducer
Without LFIBER Laser Speckle Reducer





With LFIBER Laser Speckle Reducer





Specifications of Laser Speckle Reducer (Fiber Optical Beam Homogenizer)
Fiber Core/Cladding (μm) 105/125, 200/220, 300/330, 400/440, 600/660
Numerical Aperture 0.22
Operating Wavelength (nm) 400-1800 nm
Transmission Efficiency ≥90%
Input/output Fiber Pigtail Length (m) 0.5, 1.0, 1.5, 2.0, etc.
Connector Types SC/PC, FC/PC, ST, SMA905, etc.
Housing/Package Type Steel tube, or box
Fiber Jacket/Tubing Bare fiber (without jacket), Φ900μm loose tube, Φ2.0mm or Φ3.0mm cable
Notes:
- For requests please specify the fiber core diameter, numerical aperture (NA), operating wavelengths, operating power, connector types, and input/output fiber pigtail length.
- This laser speckle reducer (fiber optical beam homogenizer) is customizable and the above specifications are subject to change without notice.