Hatice Altug

We demonstrated lasing from a high quality-factor photonic crystal surface mode, which brings several advantages for easy fabrication and efficient coupling. Temporal measurements indicate nearly ring-down time limited response.

We demonstrated high-speed photonic crystal nanocavity lasers with response time as short as ~2ps and direct modulation speeds exceeding 100 GHz. Such high-speed characteristics are enabled by the use of cavity quantum electrodynamics effects such as strong spontaneous emission rate enhancement

We have experimentally studied polarization properties of the two-dimensional coupled photonic crystal microcavity arrays and observed a strong polarization dependence of the transmission and reflection of light from the structures—effects that can be employed in building miniaturized polarizing optical components. Moreover, by combining these properties with a strong sensitivity of the coupled bands on the surrounding refractive index, we have demonstrated a detection of small refractive-index changes in the environment, which is useful for construction of biochemical sensors.

We recently proposed two-dimensional coupled photonic crystal microcavity arrays as a route to achieve a slow-group velocity of light (flat band) in all crystal directions. In this letter we present the experimental demonstration of such structures with a measured group velocity below 0.008c and discuss the feasibility of applications such as low-threshold photonic crystal lasers with increased output powers, optical delay components, and sensors.

We demonstrate a new type of laser composed of an array of coupled photonic crystal nanocavities that enables high differential quantum efficiency and output power, together with a low threshold power comparable to those of single photonic crystal cavity lasers. In our experiment, the laser efficiency increases faster than the lasing threshold with an increase in the number of coupled cavities. We observe a single mode lasing and measure the output powers that are two orders of magnitude higher than in single nanocavity lasers. Finally, we study the laser behavior theoretically and show that the benefits resulting from the coupling of cavities are due to strong cavity effects such as the enhanced spontaneous emission rate.

We have experimentally studied polarization properties of the two-dimensional coupled photonic crystal microcavity arrays, and observed a strong polarization dependence of the transmission and reflection of light from the structures - the effects that can be employed in building miniaturized polarizing optical components. Moreover, by combining these properties with a strong sensitivity of the coupled bands on the surrounding refractive index, we have demonstrated a detection of small refractive index changes in the environment, which is useful for construction of bio-chemical sensors.