Antenna coupled spintronic terahertz emitters driven by a 1550 nm femtosecond laser oscillator
We demonstrate antenna coupled spintronic terahertz (THz) emitters excited by 1550 nm, 90 fs laser pulses. Antennas are employed to optimize THz outcoupling and frequency coverage of ferromagnetic/nonmagnetic metallic spintronic structures. We directly compare the antenna coupled devices to those without antennas. Using a 200 mm H dipole antenna and an ErAs:InGaAs photoconductive receiver, we obtain a 2.42 fold larger THz peak peak signal, a bandwidth of 4.5 THz, and an increase in the peak dynamic range (DNR) from 53 dB to 65 dB. A 25 mm slotline antenna offered 5 dB larger peak DNR and a bandwidth of 5 THz. For all measurements, we use a comparatively low laser power of 45 mW from a commercial fiber coupled system that is frequently employed in table top THz time domain systems.We demonstrate antenna coupled spintronic terahertz (THz) emitters excited by 1550 nm, 90 fs laser pulses. Antennas are employed to optimize THz outcoupling and frequency coverage of ferromagnetic/nonmagnetic metallic spintronic structures. We directly compare the antenna coupled devices to those without antennas. Using a 200 mm H dipole antenna and an ErAs:InGaAs photoconductive receiver, we obtain a 2.42 fold larger THz peak peak signal, a bandwidth of 4.5 THz, and an increase in the peak dynamic range (DNR) from 53 dB to 65 dB. A 25 mm slotline antenna offered 5 dB larger peak DNR and a bandwidth of 5 THz. For all measurements, we use a comparatively low laser power of 45 mW from a commercial fiber coupled system that is frequently employed in table top THz time domain systems.
Applied Physics Letters