THz calculators
Five analysis tools and four conversions that come up in every terahertz experiment. Everything runs in your browser; nothing is sent anywhere.
Thickness analysis
Drop in a time-domain scan and read off sample thickness and refractive index. Where the internal echo is resolved, both are solved together — no assumed index, no calibration sample. Runs in the browser; nothing is sent anywhere.
Open tool →Paint thickness analysis
Every coat of an automotive paint stack from one reflection scan — clearcoat, basecoat, primer, e-coat. Their echoes overlap inside the pulse, so the whole waveform is fitted at once. Tells you which coats are actually there.
Open tool →Terahertz transmission
A reference scan and a sample scan in, transmission out. Both transformed, the spectra drawn against the noise floor so you can see where the data ends, and refractive index and absorption from a thickness. Linear, per cent, log or dB.
Open tool →Organic crystal phase matching
What thickness of DAST, DSTMS, OH1 or BNA gives the most terahertz, and where the band ends. Coherence length, the phonon, and output against thickness, from indices you can replace with your own measurements.
Open tool →EO detection bandwidth
How much bandwidth a GaP or ZnTe electro-optic detector actually gives you. Pick crystal, thickness, probe wavelength and pulse duration; the curve shows where velocity mismatch and the phonon cut you off.
Open tool →Spectral unit converter
TDS scan range ↔ resolution
Frequency resolution is set by the length of the time trace: Δf = 1/T.
PCA Scanner: 600 ps / < 2 GHz basic, 3 ns / < 0.5 GHz option.
Diffraction-limited spot
d = 1.22 λ f / D.
RIGI field of view
Active area of the focal-plane array, before the objective.
Application notes
What these tools are doing, and where each method quietly gives a wrong answer.
Refractive index and absorption from a THz-TDS measurement
How the standard thick-slab extraction works, what it assumes, and the four places it quietly gives you a wrong answer: etalons, phase unwrapping.
Read it →Choosing an electro-optic crystal for a target bandwidth
GaP, ZnTe, GaSe and BBO compared honestly. Why velocity mismatch, not material quality, sets your detection bandwidth.
Read it →Organic crystal thickness: why thicker stops helping
DAST, DSTMS, OH1 and BNA. Coherence length, terahertz absorption and pump absorption each cap the useful thickness.
Read it →Dynamic range, and where your data stops being data
Bandwidth claims mean nothing without a dynamic range to go with them. How to measure the noise floor honestly.
Read it →Water vapour lines and what they do to a transmission spectrum
Why atmospheric absorption lines throw spikes into a transmission ratio, why purging is the real fix.
Read it →