Wasatch Photonics

Transmission gratings open up many design options for the optical designer. In this tech note, we consider one special type: volume phase holographic (VPH) gratings. With benefits ranging from superior optical performance and design flexibility to robustness and consistency, VPH gratings are ideal for applications like laser pulse compression, spectroscopy, optical coherence tomography, and astronomy.

Raman spectroscopy is emerging as a rapid, portable tool to test premium liquors for evidence of adulteration or substitution –problems relevant in the rising production of pisco in Peru, where the liquor must originate from specific grape varieties and regions. Here we demonstrate the ability of 1064 Raman to distinguish pure pisco from mixtures, identify the specific grape variety, and quantify both ethanol and methanol content with a high degree of accuracy – thus validating origin, quality, and safety.

Does building your own OCT spectrometer really get you the clearest image? Creating a high-performance spectrometer for SD-OCT imaging requires a deep understanding of the finer points of both OCT theory and spectrometer design. In this tech note, we'll explain the most important parameters and contributors, then model the best available off-the-shelf lenses vs custom-designed optics to see just how the two compare. The difference in performance will surprise you…

Traditional thinking is that compact spectrometers do not offer the sensitivity or speed needed to compete with benchtop fluorimeters for many fluorescence measurements. We explain how limit of detection (LOD) and limit of quantitation (LOQ) are defined and measured, and challenge that preconception by demonstrating picomolar LOD for fluorescein with a compact, cost-effective spectrometer capable of capturing 50 ms scans with ease.