Raman measurements in water using a high‐power light‐emitting diode

Abstract

A low-noise Raman signal of water at 3300 cm −1 was detected using a blue (465 nm) light-emitting diode (LED) with an output power of 0.5 W. The linewidth of the LED emission spectrum (800 cm −1 / was larger than the intrinsic width of the detected Raman feature (400 cm −1 /. Nevertheless, the comparison of the Raman spectra from distilled and potable water demonstrated that this novel technique is applicable to the normalization of fluorescence signals in water and water-based solutions.

Raman spectroscopy with LED excitation source

“…Thus, there exists an intriguing opportunity to develop a low‐cost solution for Raman spectroscopy based on these broadband light sources, assuming the excitation energy of the broad light sources can be efficiently utilized for Raman spectroscopy with good spectral resolution. Earlier, broadband light emitting diode was successfully employed to detect Raman signal from water; however, no high spectral resolution measurements were possible in that arrangement.…”

Polarization‐resolved high‐resolution Raman spectroscopy with a light‐emitting diode

“…Over the past ten years, a few attempts to employ light‐emitting diodes (LEDs) as light sources in Raman spectroscopy have been made . The motivation for this is obvious as LEDs are inexpensive and robust, have long lifetimes, and low power consumption, and hence offer the possibility of building low‐cost spectroscopy instrumentation.…”

“…Over the past ten years, a few attempts to employ light-emitting diodes (LEDs) as light sources in Raman spectroscopy have been made. [1][2][3][4] The motivation for this is obvious as LEDs are inexpensive and robust, have long lifetimes, and low power consumption, and hence offer the possibility of building low-cost spectroscopy instrumentation. However, the main disadvantage of LEDs is their broad bandwidth, which significantly limits the achievable spectral resolution in a Raman experiment.…”

Low-picomolar limits of detection using high-power light-emitting diodes for fluorescence

“…[9][10][11][12][13] In more sophisticated instrumentation, new prototype LEDs operating in the mid-UV have been used with [14][15][16] and without 17 timediscriminating detectors. While many of the aforementioned detectors have only studied model compounds, other reports show that LEDs can also be used in interesting applications such as detecting DNA, 18 counting cells, 19,20 Raman measurements, 21 anisotropy decay, 22,23 and sensing environmental gases. 1,[24][25][26][27][28][29][30][31][32] LEDs offer an alternative to the traditional light sources for fluorescence: lasers and broadband light sources.…”