Lasers for Raman spectroscopy and microscopy
Skylark Lasers offers high power, single frequency laser sources with excellent beam quality, spectral purity, and stability for Raman and other spectroscopy applications. With long-term power and wavelength stability, our compact DPSS lasers at 320 and 532 nm are ideal for Raman spectroscopy and microscopy applications.
Spectroscopy and microscopy applications
Our customers select our ultra-stable, high precision laser sources to support their work across various Raman spectroscopy and microscopy applications.
Materials science, inspection and characterisation
Nonlinear optical imaging
CW C-DPSS single frequency lasers for Raman spectroscopy and microscopy
Our lasers have high degrees of spectral purity (>70 dB) with the added benefit of a narrow linewidth <1 MHz. The lasers can be tailored for more demanding applications reaching high output powers from a footprint.
The most common Raman spectroscopy set up for our ultraviolet wavelength lasers involves integration into a spectrometer system and the use of bandpass filters to isolate the desired Raman-shifted wavelengths and enhance the signal-to-noise ratio while improving spectral clarity.
Ideal laser specifications for Raman spectroscopy and microscopy
Raman spectroscopy is an analytical technique used and materials science to study the vibrational, rotational, and other low-frequency modes of molecules. It provides valuable information about the chemical composition and molecular structure of substances.
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.
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. The most frequently requested wavelength for Raman spectroscopy applications is 532 nm, but there is an increasing demand for blue and UV sources.
The ideal signal-to-noise ratio (SNR) for a laser used in Raman spectroscopy applications should be high enough to ensure that the Raman signals from the sample are clearly distinguishable from the background noise, with higher SNR generally leading to more reliable and accurate results.
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. A laser with a narrow linewidth can help enhance the signal-to-noise ratio by reducing spectral interference and allowing better resolution of Raman peaks.
Beam quality and spectral purity
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.