Explained: How Broadband Light Sources Have Advanced Spectroscopy?

In the past, discharging lamps, colour lasers and optical parametric oscillators were the only useful sources for spectroscopy. However, with the introduction of new technologies, spectroscopy has advanced to a new level. Supercontinuum lasers, light-emitting diodes, and laser-driven plasma technologies are new models of broadband light sources.

Because spectroscopy systems rely on light sources, new broadband light sources open up new opportunities for spectroscopists. Broadband light sources were only available for much of the last century.

However, a new generation of relatively sturdy broadband light sources is now gaining a place in the spectroscopist’s toolset. From supercontinuum lasers, plasma sources driven by lasters, to Superluminescent diodes or SLEDs are now being used in spectroscopic applications.

How Broadband Light Sources Have Advanced Spectroscopy?

Let’s take a quick look at each of these three types of broadband light sources to see how they’ve advanced spectroscopy.

Supercontinuum Lasers For Spectroscopy

A supercontinuum is created when one or more spatial processes expand the frequency range of an electron beam. Depending on the medium in which the effect occurs, the processes underlying supercontinuum generation are diverse and complex.

These broadband light sources are analogous to broadband lamps that have been converted into lasers. These instruments’ capabilities are put to use in spectroscopy in a variety of ways, including the development of novel mid-infrared absorption spectroscopy, optical coherence tomography, and visible cavity-enhanced spectroscopy setups.

Laser-Driven Light Sources For Spectroscopy

As previously stated, laser plasmas have been used as broadband light sources for spectroscopy in the past, but they have traditionally been found to be too unstable or weak to be useful for analytical spectroscopy.

This one-of-a-kind light source improves spectroscopy from near-infrared to ultraviolet wavelengths. As predicted by the reference work, Laser-driven broadband light sources have enabled numerous advances in the UV. For example, quantitative spectral analysis of biomolecules has been made possible using ultraviolet microscopy. Thanks to the ultraviolet wavelength, sub-cellular spatial resolution is possible.

Superluminescent Diodes For Spectroscopy

The most recent broadband light sources are superluminescent light-emitting diodes, which have only recently become available across a wide spectral spectrum.

The biggest problem with commercial LED lighting has been figuring out how to make both high-power, high-efficiency LEDs and colour blends that are appealing to the human eye.

The challenge in spectroscopy is different. Spectroscopists seek specific colors (ideally, tunable sources), high spectral purity or reproducibility, and high stability. LEDs face a unique challenge in terms of performance stability as a function of temperature. Accessing electronic transitions of environmentally significant gas molecules with UV sources has been a particular desire and challenge.

Summary: Lamps, traditional plasmas, globars, and the Sun are no longer the only broadband light sources. These applications range from ultraviolet to infrared. Consider one of these new sources the next time you’re looking for a new application. Because of the combination of brightness, collimation, spectral range, and affordability, a new source could be your promising spectroscopic future.

Inphenix is a laser and light source manufacturer based in the United States that produces a variety of products such as O-band optical amplifiers, distributed feedback lasers, broadband light sources, VCSELs, and swept-source lasers. Visit their website to find out more about their high-quality products and services.