Dynamic Light Scattering
Dynamic Light Scattering (DLS) is a technique used to measure the size of small particles suspended in a liquid. Oxxius lasers provide the stable, low-noise illumination required to perform these measurements with precision.
Principles of DLS
What Dynamic Light Scattering (DLS) consists of?
Particles suspended in a liquid sample are illuminated by a coherent light beam, part of which is scattered by these particles. As in the speckle phenomenon, the intensity of the scattered light fluctuates due to changes in the relative phase between contributions from each particle. The detector collects this fluctuating signal and a processing algorithm evaluates its degree of self-coherence. Once quantified, this degree of self-coherence reveals the size of the particles under study.
Laser requirements & multi-laser configurations
Why are lasers used for DLS?
Dynamic Light Scattering requires a coherent light source that can be tightly focused onto a small volume within the sample, capabilities naturally provided by lasers.
Other common requirements include:
- A stable output with minimal optical noise
- Low power consumption and a compact footprint for easy integration
- Wavelengths in the red–infrared range, preferred for minimizing sample fluorescence and ensuring greater penetration depth in turbid liquids (though other wavelengths may be suitable in specific cases)
- A high-quality beam free of artefacts around its central distribution
Oxxius DPSS single-frequency lasers
Why choose Oxxius lasers for DLS?
Oxxius has developed a unique monolithic cavity technology, protected by more than ten patents, that sets our DPSS lasers apart.
- Up to 800 mW through a TEM00 beam with a low (< 1.1) quality factor and no parasit artefacts
- High-purity spectrum: our resonator design ensures a spectrum free of detrimental side peaks, with a coherence length of several meters
- Multiple wavelengths available in the visible–infrared region: 532 nm, 976 nm, and 1064 nm. Additional options such as 633 nm or 785 nm are available using other technologies
- Ultra-stable output with no mode hops
- Optional injection system ensuring >70% coupling efficiency into a single-mode fiber
Together, these features ensure that Oxxius DPSS lasers deliver the power, coherence, and stability required for reliable dynamic light scattering.
633 nm narrow-linewidth DPSS laser
Featured product for DLS: LBX-633S
- Wavelength : 633 nm
- Output power up to 40 mW (continuous wave)
- Coherence length > 1 m
- Beam quality factor < 1.1 (though fiber injection)
- Operating temperature: 10°C to 35°C
- Power stability < ± 1.0%
The LBX-633S is ideally suited for DLS delivering a stable and coherent signal with an exceptionally clean beam profile.
Product portfolio for DLS
Related products and options
- FC-SM – Single-mode fiber injection accessory
- LCX-532S – Single-frequency laser delivering up to 300 mW at 532 nm in a compact 100×40 mm housing
- L1C-MPA – Optical power adjustment module with no added disturbances
With Oxxius StaxxBeam models, you benefit from robust laser sources that provide a coherent, stable signal over a high-quality beam, the foundation of dependable dynamic light scattering.
