Gain enhanced Fano resonance in a coupled photonic crystal cavity-waveguide structure.

Systems with coupled cavities and waveguides have been demonstrated as optical switches and optical sensors. To optimize the functionalities of these optical devices, Fano resonance with asymmetric and steep spectral line shape has been used. We theoretically propose a coupled photonic crystal cavity-waveguide structure to achieve Fano resonance by placing partially reflecting elements in waveguide.

Ultrafast optical switching using photonic molecules in photonic crystal waveguides.

We study the coupling between photonic molecules and waveguides in photonic crystal slab structures using finite-difference time-domain method and coupled mode theory. In a photonic molecule with two cavities, the coupling of cavity modes results in two super-modes with symmetric and anti-symmetric field distributions. When two super-modes are excited simultaneously, the energy of electric field oscillates between the two cavities.

Longitudinal wave function control in single quantum dots with an applied magnetic field.

Controlling single-particle wave functions in single semiconductor quantum dots is in demand to implement solid-state quantum information processing and spintronics. Normally, particle wave functions can be tuned transversely by an perpendicular magnetic field. We report a longitudinal wave function control in single quantum dots with a magnetic field.

Ultrasensitive detection of amplified spontaneous emission at 710 nm by means of picosecond collinear optical parametric amplification near degeneracy.

We report the experimental results on improving the detection of an ultraweak optical signal using a 355 nm pumped picosecond collinear optical parametric amplification (OPA). The OPA is seeded by the amplified spontaneous emission (ASE) generated in a solution of pyridine-1 dye in ethanol. The gain factor of this amplifier is determined as ~1.