Effect of Gravity on the Vertical Force of an Oscillating Wedge at Free Surface

A wedge oscillating vertically at free surface with frequency ranging from wave frequencies and slamming frequencies has been studied. The focus of this work has been on the gravity effect on the vertical forces acting on the wedge, especially the definition of the limits of gravity-dominant and gravity-negligible conditions and quantification...

The Lateral Motion of Wafer under the Influence of Thin-film Flow

Atomic layer deposition (ALD) is a newly developed technique in solar cell manufacturing which is based on sequential chemical interaction between precursor gases and the substrate of the wafer. These gases react with the substrate one at a time repeatedly until the growing atomic layer is sufficiently deposited onto the wafer. Levitech is a...

Hot electron bolometer heterodyne receiver with a 4.7-THz quantum cascade laser as a local oscillator

We report on a heterodyne receiver designed to observe the astrophysically important neutral atomic oxygen [OI] line at 4.7448?THz. The local oscillator is a third-order distributed feedback quantum cascade laser operating in continuous wave mode at 4.741?THz. A quasi-optical, superconducting NbN hot electron bolometer is used as the mixer. We...

Frequency and amplitude stabilized terahertz quantum cascade laser as local oscillator

We demonstrate an experimental scheme to simultaneously stabilize the frequency and amplitude of a 3.5 THz third-order distributed feedback quantum cascade laser as a local oscillator. The frequency stabilization has been realized using a methanol absorption line, a power detector, and a proportional-integral-derivative (PID) loop. The amplitude...

Terahertz heterodyne receiver based on a quantum cascade laser and a superconducting bolometer

We report the first demonstration of an all solid-state heterodyne receiver that can be used for high-resolution spectroscopy above 2?THz suitable for space-based observatories. The receiver uses a NbN superconducting hot-electron bolometer as mixer and a quantum cascade laser operating at 2.8?THz as local oscillator. We measure a double...