Terahertz in-line digital holography of dragonfly hindwing: amplitude and phase reconstruction at enhanced resolution by extrapolation

TL;DR

This study demonstrates terahertz digital holography of a dragonfly hindwing, achieving enhanced resolution through extrapolation and phase retrieval, revealing features as small as 35 micrometers.

Contribution

Introduces a novel statistical method for true intensity measurement and applies hologram extrapolation to improve resolution in THz biological imaging.

Findings

Achieved 35 μm resolution in THz holography of biological specimen.

Successfully reconstructed amplitude and phase images from a single hologram.

Enhanced resolution beyond detector size using hologram extrapolation.

Abstract

We report here on terahertz (THz) digital holography on a biological specimen. A continuous-wave (CW) THz in-line holographic setup was built based on a 2.52 THz CO2 pumped THz laser and a pyroelectric array detector. We introduced novel statistical method of obtaining true intensity values for the pyroelectric array detector's pixels. Absorption and phase-shifting images of a dragonfly's hind wing were reconstructed simultaneously from single in-line hologram. Furthermore, we applied phase retrieval routines to eliminate twin image and enhanced the resolution of the reconstructions by hologram extrapolation beyond the detector area. The finest observed features are 35 {\mu}m width cross veins.