Harnessing slow light

A. I. Musorin, Margarita I. Sharipova, T. V. Dolgova +2 more

The speed of light is medium-dependent, and when the properties of the medium can be chosen---as in a photonic crystal---light can be slowed to the point where it can be ``stored'' or handily manipulated. The authors use a $m\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}g\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}o\phantom{\rule{0}{0ex}}p\phantom{\rule{0}{0ex}}h\phantom{\rule{0}{0ex}}o\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}o\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}c$ crystal to harness the Faraday effect, and realize $t\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}m\phantom{\rule{0}{0ex}}e-r\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}s\phantom{\rule{0}{0ex}}o\phantom{\rule{0}{0ex}}l\phantom{\rule{0}{0ex}}v\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}d$ rotation of the polarization of a single femtosecond laser pulse. This achievement bodes well for photonic applications such as spatial light modulators, and holographic memory for optical computing.

Rachel Pei Chin Won

Thomas Y. L. Ang, Nam Quoc Ngo

We present an analytical study on the effects of coupler-induced localized backscattering (CILB) on the nature of superluminal and subliminal propagations in a traveling wave microresonator (TWMR). It is found that in the weak CILB regime, the flexibility to control the light propagation velocity is improved, and fast and slow light with high output power can be generated for a TWMR with a small net optical gain.

Bin Zhang, Yaodong Sun, Yi Xu +6 more

Optical loss is generally perceived to be an adverse effect in integrated optics. Herein, in contrast, we propose a mechanism to harness the loss in a coupled ${\rm {high-}}{\! Q}$ resonators system to realize on-chip electromagnetically induced transparency (EIT). The increasing loss of one of the coupled resonators results in a difference in ${Q}$ factor, leading to EIT generation. This optical loss-induced EIT is studied analytically using the coupled-mode theory and demonstrated experimentally in chalcogenide coupled microring resonators. By taking advantage of the chalcogenide phase change materials that feature exceptional optical property contrasts, we further demonstrate the loss-induced mechanism to realize fast and nonvolatile responses between the EIT state and the critical coupling state in a monolithically integrated chip. Our results provide a new perspective to harvest the negative loss effect of coupled resonators for tunable photonic devices, which might shed new light on the design ideology for on-chip slow-light optical components.