Giant electron-mediated phononic nonlinearity in semiconductor-piezoelectric heterostructures.

Efficient and deterministic nonlinear phononic interactions could revolutionize classical and quantum information processing at radio frequencies in much the same way that nonlinear photonic interactions have at optical frequencies. Here we show that in the important class of phononic materials that are piezoelectric, deterministic nonlinear phononic interactions can be enhanced by orders of magnitude via the heterogeneous integration of high-mobility semiconductor materials. To this end, a lithium niobate and indium gallium arsenide heterostructure is utilized to produce the most efficient three- and four-wave phononic mixing to date, to the best of our knowledge.

110 GHz, 110 mW hybrid silicon-lithium niobate Mach-Zehnder modulator.

High bandwidth, low voltage electro-optic modulators with high optical power handling capability are important for improving the performance of analog optical communications and RF photonic links. Here we designed and fabricated a thin-film lithium niobate (LN) Mach-Zehnder modulator (MZM) which can handle high optical power of 110 mW, while having 3-dB bandwidth greater than 110 GHz at 1550 nm. The design does not require etching of thin-film LN, and uses hybrid optical modes formed by bonding LN to planarized silicon photonic waveguide circuits.

Towards single-chip radiofrequency signal processing via acoustoelectric electron-phonon interactions.

The addition of active, nonlinear, and nonreciprocal functionalities to passive piezoelectric acoustic wave technologies could enable all-acoustic and therefore ultra-compact radiofrequency signal processors. Toward this goal, we present a heterogeneously integrated acoustoelectric material platform consisting of a 50 nm indium gallium arsenide epitaxial semiconductor film in direct contact with a 41° YX lithium niobate piezoelectric substrate. We then demonstrate three of the main components of an all-acoustic radiofrequency signal processor: passive delay line filters, amplifiers, and circulators.

Investigation of a Solid-State Tuning Behavior in Lithium Niobate.

Electric field-based frequency tuning of acoustic resonators at the material level may provide an enabling technology for building complex tunable filters. Tunable acoustic resonators were fabricated in thin plates (h/ λ  ∼  0.05 ) of X-cut lithium niobate (LiNbO) (90°, 90°, ψ = 170 ).

Understanding heterogeneity in Genesis diamond-like carbon film using SIMS analysis of implants.

An amorphous diamond-like carbon film deposited on silicon made at Sandia National Laboratory by pulsed laser deposition was one of several solar wind (SW) collectors used by the Genesis Mission (NASA Discovery Class Mission #5). The film was ~1 μm thick, amorphous, anhydrous, and had a high ratio of - bonds (>50%). For 27 months of exposure to space at the first Lagrange point, the collectors were passively irradiated with SW (H fluence ~2 × 10 ions cm; He fluence ~8 × 10 ions cm).

In vivo evaluation of tetrahedral amorphous carbon.

The in vivo behavior and tissue reaction to tetrahedral amorphous carbon (ta-C) has been evaluated for periods of up to 6 months in SV129 mice. Two sample types were tested--silicon die coated with ta-C (n = 53) and micromachined particles (n = 40). The coated samples were compared to uncoated silicon die (n = 22).

Experimental demonstration of a laterally deformable optical nanoelectromechanical system grating transducer.

We experimentally demonstrate operation of a laterally deformable optical nanoelectromechanical system grating transducer. The device is fabricated in amorphous diamond with standard lithographic techniques. For small changes in the spacing of the subwavelength grating elements, lossy propagating resonant modes in the plane of the grating cause a large change in the optical reflection amplitude.

Laterally deformable nanomechanical zeroth-order gratings: anomalous diffraction studied by rigorous coupled-wave analysis.

We describe a novel optomechanical device that produces strong reflectance and polarization modulation of incident light. The structure is based on a suspended nanomechanical grating with lateral deformability, and rigorous coupled-wave analysis has been used to fully model the optical properties of the device. The grating consists of two interdigitated gratings that may be moved with respect to each other with an applied force.