Raman Spectroscopy and Microscopy

Selecting the appropriate laser source for Raman Spectroscopy can be difficult. It is crucial to consider various factors such as the wavelength, the spectral linewidth, and the beam quality of the laser source. Skylark Lasers offer a range of solutions to alleviate the limitations that Raman spectroscopy measurements typically face, such as the small Raman scattering cross-sections and intrinsic noise sources like sample autofluorescence.

Lasers for Raman Spectroscopy and Microscopy:

When a laser is incident on a sample, most of the photons will be scattered elastically and will not be subject to any energy change, known as Rayleigh Scattering. Raman scattering events are significantly more infrequent, only around 1 in a million incident photons, but the consideration of these inelastically scattered photons, where a change in frequency (or Stokes shift) can be observed, allows a range of information about the sample to be determined.

There are three main considerations for selection a laser source for Raman spectroscopy:

1. Wavelength: The strength of the Raman signal is directly dependent on the wavelength of the laser source, where lower wavelengths will produce stronger Raman signals, as well as allowing for higher spatial resolution.

2. Linewidth and spectral purity: The spectral linewidth of the laser source should also be considered, as it will limit the possible resolution of the Raman measurement and so the minimum energy change that can be determined.#

3. Beam quality: The beam quality is related to the possible spatial resolution. Here, single transverse mode beams (TEM00) are vital for confocal Raman Spectroscopy in particular, allowing for high spatial control in all three axes, improving spatial resolution, and decreasing background effects.

320 NX Laser

532 NX Laser

Our single frequency continuous wave laser sources offer unrivalled wavelength stability and a narrow linewidth. Our lasers have high degrees of spectral purity (>70 dB) with the added benefit of a narrow linewidth <1 MHz. Our lasers can be tailored for more demanding applications reaching high output powers on a small footprint.