Laser speckle reducers

Optotune’s laser speckle reducers offer a compact turnkey solution for speckle reduction and beam homogenization using an oscillating AR-coated fused-silica diffusor. The reliable actuation technology delivers stable performance for over 40,000 hours.

From speckle-free laser illumination in fluorescence microscopy to brighter, higher-contrast laser projection with expanded color gamut, these systems enhance signal quality, increase detection accuracy, and effectively eliminate unwanted laser speckle.

  • Compact design with large aperture
  • Driving electronics integrated on flex-cable​
  • Robust design with long operational lifetime​
  • Built-in amplitude stabilization

Optotune’s laser speckle reducers (LSR) use a single thin steel structure that is driven into resonance by pulsing an actuating coil, generating a strong reluctance force. Thanks to its high Q-factor, it achieves large amplitudes of up to 800 µm while maintaining very low power consumption of only 50 mW. A second coil continuously monitors the amplitude in closed loop for stable, accurate operation. The bearing-free design is highly robust and built to withstand shocks of up to 500 g. The speckle reducers are factory calibrated.

The design is <6 mm thin and lightweight (11 g). Compared to spinning-disk diffusors, there is no motor blocking the central optical area, ensuring optimal use of the diffuser surface. Its compact form factor includes fully integrated driving electronics and supports a variety of diffuser materials. Combined with an operational lifetime exceeding 40,000 hours, the system offers long-term reliability and maximum optical efficiency.

Static diffusor (LSR OFF): 0.26 speckle contrast​

Dynamic diffusor (LSR ON): 0.06 speckle contrast

Product variants

Compact de-speckling

Optotune’s LSR-4C reduces speckle through dynamic diffusion, rapidly moving a diffusor to average multiple interference patterns and deliver a uniform, speckle-free beam. With its large 18.5 × 18.5 mm clear aperture, it is built for high-power, large-beam applications such as laser cinema projection. The metallic frame and reluctance-based actuation ensure reliable motion.

Key advantages:
  • ​Large 18.5 × 18.5 mm clear aperture supports high power and large beam diameters​
  • Compact electronics with closed-loop resonance stabilization​
  • Optional dual 90° diffusor configuration for optimized bi-directional de-speckling​
  • Integrated error signal for system monitoring
Compact de-speckling

Optotune’s LSR-5 reduces speckle through dynamic diffusion, rapidly moving a diffuser to average multiple interference patterns and deliver a uniform, speckle-free beam. With its 5 × 5 mm clear aperture, it is a cost effective alternative to the LSR-4C for applications that do not require the very large clear aperture, such as metrology and medical. The metallic frame and reluctance-based actuation ensure reliable motion.

Key advantages:
  • Cost effective solution for small diffusor size​
  • 5 × 5 mm clear aperture supports high power laser beams​
  • Compact electronics with closed-loop resonance stabilization​
  • Integrated error signal for system monitoring​
Product nameDiffusor size (mm)Oscillation typeOscillation amplitude (mm) p-pResonance frequency (Hz)​ *Operating lifetime (hours)Diffusorhf:tax:tax-diffusor-size-mmhf:tax:tax-resonance-frequency-hz
LSR-4C18.5 x 18.51D (linear)0.8120>40’000Fused silica 8.5° DVIS or uncoatedDetails18-5-x-18-5120
LSR-5​5 x 51D (linear)0.8138>40’000Fused silica 8.5° DVIS or uncoatedDetails5-x-5138
* depends on diffusor weight​

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