Influence of substrate-lens design in terahertz time-domain spectroscopy

Rudd, J. V.; Mittleman, Daniel M.

doi:10.1364/josab.19.000319

Cited by 140 publications

(42 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The HSL had a distance of 2000 µm from the substrate to the tip of the lens, and its geometry was determined by the relations given in Ref. 4. Reflection losses due to the interface between the HSL and substrate were neglected.…”

Section: Resultsmentioning

confidence: 99%

“…4 In Fig. 3(c) the ratio P 45 •(45 • ) is plotted at different frequencies for a GRIN lens optimized for 1 THz with φ = 45…”

Section: Resultsmentioning

confidence: 99%

“…Contrary to theoretical methods applied previously for ordinary THz lenses, 3,4 e.g. HSL's, the microstructuring proposed here requires that one applies a more rigorous solution of Maxwell's equations taking into account the full-wave nature of the radiation, reflections inside the lens, interference, etc.…”

Section: Theoretical Approachmentioning

confidence: 99%

“…However, due to the inherent design of a typical PCA, a large part of the emitted THz radiation is trapped within the semiconductor substrate. To avoid this, it is customary to mount a HSL to the PCA to out-couple and collimate the radiation, 3,4 as illustrated in Fig. 1(a).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Microstructured gradient-index lenses for THz photoconductive antennas

et al. 2016

View full text Add to dashboard Cite

A new type of substrate lens for photoconductive antennas (PCA’s) based on sub-wavelength microstructuring is presented and studied theoretically by the use of Greens function integral equation methods (GFIEM’s). By etching sub-wavelength trenches into a flat substrate, the effective dielectric constant can be designed to function like a gradient index (GRIN) lens. The proposed GRIN substrate lenses have sub-mm dimension, which is smaller than the dimensions of a typical hyper-hemispherical substrate lens (HSL), and could enable fabrication of arrays of closely packed PCA’s with individual lenses integrated directly into the PCA substrate. The performance of different GRIN lenses is compared to a HSL and shown to be comparable with regards to the terahertz radiation extraction efficiency, and it is shown that the collimating properties of these GRIN lenses can be tailored by changing the parameters used for microstructuring.

show abstract

Section: Resultsmentioning

confidence: 99%

“…4 In Fig. 3(c) the ratio P 45 •(45 • ) is plotted at different frequencies for a GRIN lens optimized for 1 THz with φ = 45…”

Section: Resultsmentioning

confidence: 99%

Section: Theoretical Approachmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Microstructured gradient-index lenses for THz photoconductive antennas

et al. 2016

View full text Add to dashboard Cite

show abstract

“…1. The THz radiation emitted by the photoconductive dipole antenna is pre-collimated with a High-Resistivity Si-lens of hypersemispherical shape [14,15]. The beam is guided via four off-axis parabolic mirrors PM1-PM4.…”

Section: Methodsmentioning

confidence: 99%