Terahertz emission from a large-area GaInAsN emitter

Abstract

A large-area interdigitated terahertz emitter based on molecular-beam epitaxy grown GaInAsN with an additional AlGaAs heterostructure is investigated as a terahertz source for excitation wavelengths between 1.1 and 1.5 mu m. The optical and electrical properties of the emitter material exhibit absorption up to a wavelength of 1.5 mu m and have a resistivity of 550 k Omega cm. Terahertz waves were detected by electro-optical sampling with a bandwidth exceeding 2 THz. Best performance is found for excitation wavelengths below 1.35 mu m. Furthermore the emission properties for several excitation powers are investigated, showing a linear increase in terahertz emission

1550 nm ErAs:In(Al)GaAs large area photoconductive emitters

“…This is by almost a factor of two higher THz field than generated with InGaAsN samples at the shorter wavelength of 1:3 lm. 11 The dynamic range is 47.8 dB at a few 100 GHz and still 40 dB at 2 THz at a lockin time constant of 1 s (24 dB/octave filter attenuation). We compared the performance of the sample with lateral contacts ( Fig.…”

“…We implemented the short lifetime material in a large area emitter (LAE) geometry, which has been proven to be very efficient for high power, ultra-broadband THz generation. [10][11][12][13][14] In contrast to continuous-wave operated antenna-coupled emitters, pulsed LAEs do not require a short lifetime. 12,14,15 The ErAs recombination centers, however, assist to drastically increase the resistance of the sample by a factor of at least 45 compared to unintentionally doped intrinsic InGaAs.…”

Scalable Microstructured Photoconductive Terahertz Emitters

“…Similarly to SI-GaAs based emitters the THz field increases linearly with NIR power provided by a state-of-the-art laser oscillator (demonstrated up to 0.5 W), i.e. its performance is not limited by saturation effects when driven with a laser oscillator [44]. These emitters are not suitable for 1.55 μm excitation from an erbiumdoped fiber laser, but they can be excited with ytterbium-doped fiber lasers operating around 1.1 μm.…”

“…While first attempts to produce scalable emitters on LT-In 0.53 Ga 0.47 As 0.96 lattice-matched on InP failed due to the low specific resistivity of the material, scalable emitters were fabricated successfully on materials with a lower indium content. To this end, a scalable microstructured emitter of 1 mm 2 area was patterned on a Ga 0.89 In 0.11 As 0.96 N 0.04 photoconductive layer of a thickness of 1 μm [44]. The layer, capped with an Al 0.3 Ga 0.7 As/GaAs (60 nm AlGaAs, 5 nm GaAs) heterostructure was grown by molecular-beam epitaxy on a SI-GaAs substrate [103].…”

“…Therefore InGaAs based scalable emitters are a very challenging task. While no scalable emitters for 1.55 μm excitation have been demonstrated so far, scalable emitters have been realized on InGaAsN with a smaller indium content [44]. This material allows for excitation with ytterbium-doped fiber lasers operating at 1.06 μm.…”