Biomedical subjects

H L Offerhaus

Publications and source records attributed to H L Offerhaus.

3 recordsLinked to original sources

PubMed2006

Single-frequency operation of a broad-area laser diode by injection locking of a complex spatial mode via a double phase conjugate mirror.

We demonstrate what is believed to be the first phase-coherent locking of a high-power broad-area diode to a single-frequency master laser. We use photorefractive double phase conjugation to lock the diode in a self-optimized complex spatial mode while the photorefractive crystal diffracts that complex mode in a near-diffraction-limited beam.

Journal Article↗

PubMed2005

Creating focused plasmons by noncollinear phasematching on functional gratings.

We report on the concept, generation, and first observations of focused surface plasmons on shaped gratings. The grating patterns are designed to realize focusing and directing through noncollinear phasematching. The plasmons are generated on patterned gold surfaces, and the plasmon propagation is observed using phase-sensitive photon scanning tunneling microscopy (PSTM) to extract the propagation pattern, direction, and wavelength.

Journal Article↗

PubMed2002

Photoionization microscopy.

We present the first experimental results of a technique called photoionization microscopy. Photoelectrons ejected in threshold photoionization of Xe are detected in a velocity map imaging apparatus, and interferences between various trajectories by which the electron moves from the atom to the detector are observed. The structure of the interference pattern, which contains the transverse component of the electronic wave function, evolves smoothly with the excess energy above the saddle point. The main observed features are interpreted within the framework of the semiclassical approximation.

Journal Article↗