Ferromagnetic planar Josephson junction with transparent interfaces: a φ junction proposal.

We calculate the current-phase relation of a planar Josephson junction with a ferromagnetic weak link located on top of a thin normal metal film. Following experimental observations we assume transparent superconductor-ferromagnet interfaces. This provides the best interlayer coupling and a low suppression of the superconducting correlations penetrating from the superconducting electrodes into the ferromagnetic layer. We show that this Josephson junction is a promising candidate for experimental φ junction realization.

An optimized optical system for backlit imaging.

An optimized optical system for back-illuminated imaging was developed and was applied to automotive-type fuel injectors; the system provides significantly higher light collection efficiency than standard flood illumination. An engineered diffuser is used to distribute an extended light source through a controlled range of angles, and a field lens is used to redirect the light to the camera. A ray tracing analysis provides the required source size and diffuser angle to ensure that the necessary range of ray angles is included to allow fully diffuse imaging. Direct comparison with a flood illumination system showed that the collection efficiency increased by more than two orders of magnitude without any degradation of image quality.