Lamp Source Calculator
Calculate blackbody spectral radiance and étendue-limited throughput for lamp-based optical systems.
Broadband lamp sources — tungsten-halogen, xenon arc, deuterium — are thermal or arc emitters whose spectral output and coupling efficiency are governed by two separate physics problems. This calculator addresses both. Blackbody Spectrum mode applies Planck's law and the Wien displacement law to compute peak wavelength, total exitance via the Stefan-Boltzmann relation, and spectral radiance at any user-specified wavelength, for an emitter at temperature T with emissivity ε. Étendue & Throughput mode computes the limiting étendue between a lamp arc (characterized by source diameter and collection F/#) and either a multimode fiber (core diameter and NA) or a monochromator slit, identifying which element is the throughput bottleneck and reporting the spectral flux in µW/nm. All calculations use 2019 SI exact values for h, c, and k_B.