Optics & Spectroscopy Calculators

Optics calculators cover the quantitative work of geometric optics, wave optics, and laser/photonics applications: lens equations, mirror equations, refraction (Snell's law), diffraction, dispersion, and the laser-specific calculations (Gaussian beams, spot sizes, NA-to-f-number) that come up in optical engineering. This is one of our more technically deep categories and is aimed at undergraduate physics students, photonics engineers, and optics hobbyists.

For geometric optics, the thin lens, lensmaker, and mirror equation calculators handle the standard image-distance/object-distance/focal-length relationships and the magnification calculations. Snell's law (with critical angle calculation), Brewster's angle, and focal length calculators round out the foundational tools.

For wave optics, we have diffraction grating calculations (m × λ = d × sinθ), thin-film interference (for anti-reflection coatings and optical filters), and prism dispersion (using Cauchy's dispersion equation, A + B/λ² + C/λ⁴, for the wavelength dependence of refractive index in transparent materials). For more precise dispersion modeling, the Sellmeier equation calculator handles the three-term form that's standard for optical glass specifications.

Laser and Gaussian-beam calculators include the spot size at beam waist, the beam divergence, and the conversion between numerical aperture (NA) and f-number — useful for matching laser optics to microscope objectives and fiber couplings. The optical fiber NA calculator handles single-mode and multi-mode fiber design.

For ultrafast and femtosecond laser applications, we have pulse compression and pulse-front-tilt calculators. These are specialty tools used in chirped-pulse amplification (CPA) systems and ultrafast spectroscopy setups.

For spectroscopy, the Beer-Lambert law calculator (A = ε × c × l) is the workhorse of absorption spectroscopy. The Raman wavenumber-shift calculator handles the cm⁻¹ ↔ nm conversions that come up constantly in Raman spectroscopy.

Refractive index and dispersion data follow the Schott, Ohara, and CDGM optical glass catalogs where applicable. For research-grade work, validate against the specific glass type's measured values, since different production lots and tempering states can produce small variations in refractive index.