Speckle-free digital holographic recording of a diffusely reflecting object.

We demonstrate holographic recording without speckle noise using the digital holographic technique called optical scanning holography (OSH). First, we record a complex hologram of a diffusely reflecting (DR) object using OSH. The incoherent mode of OSH makes it possible to record the complex hologram without speckle noise. Second, we convert the complex hologram to an off-axis real hologram digitally and finally we reconstruct the real hologram using an amplitude-only spatial light modulator (SLM) without twin-image noise and speckle noise. To the best of our knowledge, this is the first time demonstrating digital holographic recording of a DR object without speckle noise.

Diagnostic assay of trace lead in an ex vivo tissue using a combination electrode.

A voltametric diagnosis of trace lead was performed using macro type combination sensors of fluorine-doped graphite pencil electrodes (FPE). Two pencils were used as the reference and auxiliary instead of expensive Ag/AgCl standards and Pt counters. Under optimized conditions, a square wave (SW) stripping working curve was attained at 10-70 mg/L and a micro range of 10-70 µg/L. The developed sensor was not only inexpensive but also had a fast (90-s) accumulation time. An analytical detection limit of 10 µg/L was obtained. The results were applied to an ex vivo tissue and an artificial turf.