13 research outputs found
Hybrid silicon-organic Huygens' metasurface for phase modulation
Spatial light modulators have desirable applications in sensing and free
space communication because they create an interface between the optical and
electronic realms. Electro-optic modulators allow for high-speed intensity
manipulation of an electromagnetic wavefront. However, most surfaces of this
sort pose limitations due to their ability to modulate intensity rather than
phase. Here we investigate an electro-optic modulator formed from a
silicon-organic Huygens' metasurface. In a simulation-based study, we discover
a metasurface design immersed in high-performance electro-optic molecules that
can achieve near-full resonant transmission with phase coverage over the full
2 range. Through the electro-optic effect, we show 140 (0.79)
modulation over a range of -100 to 100 V at 1330 nm while maintaining
near-constant transmitted field intensity (between 0.66 and 0.8). These results
potentiate the fabrication of a high-speed spatial light modulator with the
resolved parameters.Comment: 10 pages, 5 figure
Electric field correlation measurements on the electromagnetic vacuum state
ISSN:0028-0836ISSN:1476-468
Broadband monolithic extractor for metal-metal waveguide based terahertz quantum cascade laser frequency combs
Terahertz waveform synthesis in integrated thin-film lithium niobate platform
Bridging the “terahertz gap“ relies upon synthesizing arbitrary waveforms in the terahertz domain enabling applications that require both narrow band sources for sensing and few-cycle drives for classical and quantum objects. However, realization of custom-tailored waveforms needed for these applications is currently hindered due to limited flexibility for optical rectification of femtosecond pulses in bulk crystals. Here, we experimentally demonstrate that thin-film lithium niobate circuits provide a versatile solution for such waveform synthesis by combining the merits of complex integrated architectures, low-loss distribution of pump pulses on-chip, and an efficient optical rectification. Our distributed pulse phase-matching scheme grants shaping the temporal, spectral, phase, amplitude, and farfield characteristics of the emitted terahertz field through designer on-chip components. This strictly circumvents prior limitations caused by the phase-delay mismatch in conventional systems and relaxes the requirement for cumbersome spectral pre-engineering of the pumping light. We propose a toolbox of basic blocks that produce broadband emission up to 680 GHz and far-field amplitudes of a few V m−1 with adaptable phase and coherence properties by using near-infrared pump pulse energies below 100 pJ.ISSN:2041-172
High performance 4.7 THz GaAs quantum cascade lasers based on four quantum wells
GaAs/AlGaAs quantum cascade lasers based on four quantum well structures operating at 4.7 THz are reported. A large current density dynamic range is observed, leading to a maximum operation temperature of 150 K for the double metal waveguide device and a high peak output power more than 200 mW for the single surface plasmon waveguide device. A continuous wave, single mode, third order distributed feedback laser with a low electrical power dissipation and a narrow far-field beam pattern, which is required for a local oscillator in astronomy heterodyne spectrometers, is also demonstrated