Optical unit converter

The optical unit converter accepts a single numeric value and its unit among nm, THz, eV, or cm−1 and returns the four related quantities: wavelength in nanometers, frequency in terahertz, photon energy in electronvolts, and wavenumber in cm−1. It is designed for physicists, optical engineers, and educators who compare optical quantities across representations used in spectroscopy, photonics, and materials science.
Under the hood, it uses standard physical constants (speed of light c, Planck's constant h, and the elementary charge e) and consistent unit definitions. The input is normalized to SI base units and then propagated to all outputs through fixed formulas to minimize rounding errors.
Key differentiators include strict validation (positive input values), robust unit handling, and transparent rounding rules. The tool supports the most common optical representations and yields outputs in conventional units used by scientists and students, enabling rapid cross-checks during experiments and coursework.
Common use cases include converting wavelength to energy for detector efficiency studies, translating spectral lines from frequency to wavenumber for material characterization, and validating photonic device designs by comparing multiple representations of the same optical transition.