Mickan, S.Shvartsman, R.Munch, J.Zhang, X.Abbott, D.2006-12-062006-12-062004Journal of optics. B, Quantum and semiclassical optics : journal of the European Optical Society, 2004; 6(8):S786-S7951464-42661741-3575http://hdl.handle.net/2440/18128Copyright © Institute of Physics and IOP PublishingLiquid transmission studies at terahertz frequencies (0.1–10 THz) are valuable for understanding solvation dynamics of salts, exploring long-range structure in mixtures and probing biomolecules in suspension. T-ray (or THz) time-domain spectroscopy, based on terahertz pulse generation from ultrafast lasers, is a sensitive technique for measuring material parameters in this frequency range. This paper proposes and demonstrates a novel technique for increasing the sensitivity and repeatability of liquid studies with T-ray time-domain spectroscopy (TDS), reducing relative parameter measurement errors below 0.0001. The proposed technique combines dual-thickness liquid measurement with rapid modulation (double-modulated differential TDS) to reduce the effect of both thickness-measurement errors and T-ray noise errors below 0.0001. The possible reduction in error is calculated and a liquid differential TDS (DTDS) prototype is demonstrated, incorporating amplitude and mean detection for near-simultaneous measurement of two T-ray waveforms.enJournal article002004118910.1088/1464-4266/6/8/0250002255650000272-s2.0-434466465256493Abbott, D. [0000-0002-0945-2674]