ABSTRACT
Patterns are broad phenomena that relate to biology, chemistry, and physics. The dendritic growth of crystals is the most well-known ice pattern formation process. Tyndall figures are water-melting patterns that occur when ice absorbs light and becomes superheated. Here, we report a previously undescribed ice and water pattern formation process induced by near-infrared irradiation that heats one phase more than the other in a two-phase system. The pattern formed during the irradiation of ice crystals tens of micrometers thick in solution near equilibrium. Dynamic holes and a microchannel labyrinth then formed in specific regions and were characterized by a typical distance between melted points. We concluded that the differential absorption of water and ice was the driving force for the pattern formation. Heating ice by laser absorption might be useful in applications such as the cryopreservation of biological samples.
ABSTRACT
For the first time, to our knowledge, a highly robust, high-bit-rate (10 Gbit/s) wavelength converter that is based on a narrow Brillouin filter is reported. The conversion takes place in a semiconductor optical amplifier (SOA) in a cross-gain-phase process. The SOA operates in a weak-modulation mode, and the exiting signal undergoes a dc reduction with a narrow spectral filter. In our system we perform spectrally narrow filtering by using a long Brillouin grating.
