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Extending the ‘flat optics’ paradigm to the nonlinear optics faces important challenges, since, for any practical situation, we are required to simultaneously achieve sub-diffraction phase control and efficient frequency conversion in metasurfaces of sub-wavelength thickness. Here, we experimentally demonstrate giant nonlinear response and continuous phase control of the giant nonlinear response in...
Gradient metasurfaces, or ultrathin optical components with engineered transverse impedance gradients along the surface have recently been demonstrated to provide control of the phase of scattered fields over sub-wavelength scale, enabling a broad range of linear optical components. More recently, sub-wavelength-thin nonlinear metasurfaces with tailored nonlinear responses have provided new degrees...
We report highly-nonlinear ultrathin metasurfaces based on coupling of plasmonic nanoresonators with intersubband nonlinearities. Nonlinear susceptibilities over 1×106 pm/V and conversion efficiencies ∼0.1% were measured for second harmonic generation in mid-infrared for 10 kW/cm2 input intensity. Complete phase control of local nonlinear response is demonstrated.
We report highly-nonlinear metasurfaces based on combining electromagnetically-engineered plasmonic nanoresonators with quantum-engineered intersubband nonlinearities. Experimentally, effective nonlinear susceptibility over 480 nm/V was measured for second-harmonic generation at normal incidence.
We report ultra-fast voltage-tunable optical response from metamaterials based coupling of plasmonic resonances in metallic nanostructures with intersubband polaritons. Over 310nm of spectral peak tuning around 7µm with 10ns response time was experimentally demonstrated.
We report highly-nonlinear metasurfaces based on coupling of electromagnetically-engineered plasmonic nanoresonators with quantum-engineered intersubband nonlinearities. Experimentally, effective nonlinear susceptibility over 50 nm/V was measured for second-harmonic generation under normal incidence.
Room-temperature, narrow-linewidth terahertz quantum cascade laser sources based on intracavity Cherenkov difference-frequency generation with emission over the 2 to 4 THz range and a maximum power of 0.12 mW is demonstrated.
Polarization stable MEMS VCSEL devices based on InP with SWG are presented. They show tuning ranges of 23nm, 1mW optical output power, Ith of 3mA and a polarization suppression ratio around 20dB.
We demonstrate for the first time a surface micro-machined micro-electro-mechanical tunable VCSEL operating at 1.95 μm with 50 nm tuning range, 1 mW output power and 2.5 mA threshold current, capable for absorption spectroscopy.
We report terahertz quantum cascade laser sources based on intra-cavity difference-frequency generation in passive nonlinear sections. Current devices provide terahertz output up to a heat sink temperature of 210 K.
The high temperature behavior of short cavity InP based VCSEL devices with 5.5 μm apertures is presented. They show record optical output powers and SMSRs beyond 50 dB over the whole temperature range.
We report terahertz quantum cascade laser sources based on intra-cavity difference-frequency generation in passive nonlinear sections. Current devices provide terahertz output up to a heat sink temperature of 210 K.
In this paper we demonstrate RT second-harmonic generation around 2.7 μm with peak output powers close to 10 μW at current densities of around 2 kA/cm2. We also discuss possible device structures for wavelengths around 3.5 μm and a future development strategy for single-mode, two-color tunable laser sources.
An injectorless quantum cascade laser design, using two 0.6 nm InAs spikes within the active zone, yielding shorter wavelength and improved performance is presented. The average pulsed output power was measured to 880 mW at 297 K.
An injectorless quantum cascade laser design, using four material compositions, and back-facet high-reflective coating is presented. The threshold current density at 300 K and the characteristic temperature were measured with 0.45 kA/cm2 and 140 K, respectively.
An injector-less quantum cascade laser is presented, which is capable of concurrent light emission at two different wavelengths (6.4 and 7.6 mum) at 77 K. The maximum operation temperature is 340 K and at 77 K the laser threshold current density is 0.19 kA/cm2. A competing approach using a single active zone for dual wavelength emission is also presented.
We present a five-level quantum-cascade laser design without injector miniband, showing small threshold current densities (0.15 kA/cm 2 at 77 K and 1.65 kA/cm2 at 300 K) and a maximum operating temperature of 420 K
We report on an unusual quantum-cascade laser design without injector miniband, designed as a five-level staircase. The aim of this design scheme is to prevent a thermal backfilling of the lower laser state, by using a double or triple LO-phonon resonance, respectively. These lasers show exceedingly small threshold current densities at low temperatures (0.2 kA/cm2 at 77 K) and a threshold voltage...
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