Photonic realizations of neural network computing hardware are a promising approach to enable future scalability neuromorphic computing. The number special purpose and photonics has accelerated on such scale that one can now speak Cambrian explosion. Work along these lines includes (i) high performance for artificial neurons, (ii) the efficient scalable implementation network’s connections, (ii...

in this study, the effects of strength and direction of the magnetic field on lid-driven cavity flow in the whole range of magnetic field strength variations, which already used in practice up to present (0 to 10 tesla), are studied. the governing equations, including conservative equations of momentum, continuity and magnetic field equations were solved numerically. momentum and continuity equ...

A vertical cavity surface-emitting laser was studied for gas-sensing applications. Properties of the 962-nm laser that were measured include side-mode suppression, wavelength tuning with temperature and current, power versus injection current, and the amplitude noise spectrum. With wavelength modulation spectroscopy, a rms noise level of 2 x 10(-4) absorbance units was achieved. The large curre...

Coherently coupled vertical-cavity surface-emitting laser arrays offer unique advantages for nonmechanical beam steering applications. We have applied dynamic coupled mode theory to show that the observed temporal phase shift between vertical-cavity surface-emitting array elements is caused by the detuning of their resonant wavelengths. Hence, a complete theoretical connection between the diffe...

A room temperature operating Vertical External Cavity Surface Emitting Laser is applied around 1550 nm to intracavity laser absorption spectroscopy analyzed by timeresolved Fourier transform interferometry. At an equivalent pathlength of 15 km, the high resolution spectrum of the semiconductor disk laser emission covers 17 nm simultaneously. A noise equivalent absorption coefficient at one seco...

We report a strong reduction of spatial coherence of the emission of large aperture vertical-cavity surface-emitting lasers when they are driven by microsecond electrical pulses. We give evidence that this is due to a breakdown of the modal emission of these lasers. The spatial decoherence manifests itself in the formation of a Gaussian far field intensity distribution. The coherence radius we ...

Orthogonal polarizations within vertical-cavity surface-emitting lasers ~VCSEL! lase at slightly different wavelengths. We describe the use of optical feedback to confine polarization variations to reproducible injection currents. An external cavity is used to select specific wavelengths that reflect back into the VCSEL, hence, changing the cavity Q for the different polarization states. With t...

The use of an air curtain directed across the aperture of an inclined open-ended cavity is examined as a method to reduce convective losses from a heated cavity. Computational fluid dynamics (CFD) simulations were conducted in two-dimensions for a range of air curtain velocities and axial cavity orientations. The greatest relative reduction in convective losses with an air curtain resulted when...

We present the results of a combined experimental and theoretical investigation of the vertical impact of a hydrophobic sphere with a water surface. Particular attention is given to characterizing the shape of the resulting air cavity in the low Bond number limit. A theoretical model is developed to describe the evolution of the cavity shape, and the pinch-off time is deduced for each of the th...