RESUMEN
We demonstrate compact tunable phased-array wavelength-division multiplexers driven by surface acoustic waves (SAWs) in the low GHz range. The devices comprise two couplers, which respectively split and combine the optical signal, linked by an array of single-mode waveguides (WGs). Two different layouts are presented, in which multi-mode interference couplers or free propagating regions were separately employed as couplers. The multiplexers operate on five equally distributed wavelength channels, with a spectral separation of 2 nm. A standing SAW modulates the refractive index of the arrayed WGs. Each wavelength component periodically switches paths between the output channel previously asigned by the design and the adjacent channels, at a fixed applied acoustic power. The devices were monolithically fabricated on (Al,Ga)As. A good agreement between theory and experiment is achieved.
RESUMEN
Photonic modulators are one of the most important elements of integrated photonics. We have designed, fabricated, and characterized a tunable photonic modulator consisting of two 180°-dephased output waveguide channels, driven by a surface acoustic wave in the GHz frequency range built on (Al,Ga)As. Odd multiples of the fundamental driven frequency are enabled by adjusting the applied acoustic power. A good agreement between theory and experimental results is achieved. The device can be used as a building block for more complex integrated functionalities and can be implemented in several material platforms.
RESUMEN
A parent whose child affected by hemophilia develops an inhibitor has to cope with strong emotions and anxieties related to the acceptance of this second diagnosis when just having severe hemophilia seems nothing compared to having antibodies that neutralize factor infusions and the possibility of uncontrolled hemorrhages. During the initial stage of adaptation to this frightening reality, a parent needs constant support by the Center staff. The period during which medical personnel and parents decide about the possibility of putting a child on an immune tolerance protocol is a crucial one; if parents feel they have been well informed about this sort of treatment and feel adequately prepared to handle situations which may arise, they will take an active role in the care of their sons and maintain a positive attitude. The fears and worries are many, the greatest of which is the constant dread of a negative outcome. The commitment of staff during the formal period of instruction, the use of a local anesthetic, play therapy and the very young age of the child were variables that made peripheral, home infusion in a 1 1/2 old on immune tolerance possible. The needs of siblings, of the parents themselves and the strong bonding between mother and child are only but a few of the psychological aspects related to immune tolerance.