Controlling light with light

Anonymous

François O. Laforge, Matthew S. Kirschner, HERSCHEL A. RABITZ

We propose a method for interactively controlling multi-species atomic and molecular systems with incoherent light. The technique is referred to as shaped incoherent light for control (SILC), which entails dynamically tailoring the spectrum of a broadband incoherent source to control atomic and molecular scale kinetics. Optimal SILC light patterns can be discovered with adaptive learning techniques where the system's observed response is fed back to the control for adjustment aiming to improve the objective. To demonstrate this concept, we optimized a SILC source to optimally control the evolving hue in near-IR to visible upconverting phosphors, which share many similarities with chemical reaction kinetics including non-linear behavior. Thus, the results suggest that SILC may be a valuable tool for the control of chemical kinetics with tailored incoherent light.

Bichen Zou, Zheng Tan, Yifu Zhu

We present a theoretical model of light controlling light in a multi-atom cavity QED system consisting of three-level atoms confined in a cavity and interacting with a control laser from free space. A signal laser is coupled into the cavity and provides two output light channels: the transmitted signal light through the cavity and the reflected signal light from the cavity. We show that with the cavity electromagnetically induced transparency manifested by the free-space control light, the amplitude and the phase of the intra-cavity signal light can be manipulated by the free-space control laser. We analyze the cavity transmitted signal light and the cavity reflected signal light, and show that the two output channels of the signal light are complementary and the cavity-atom system is a versatile system for studies of all-optical switching and cross-phase modulation at low control intensities.

Bernhard W. Adams

Chao Li, Hong Wang, Jun-Fang Wu +1 more

In this paper, we investigate the critical conditions of control light for a silicon-based photonic crystal bistable switching. By establishing a time-dependent evolution equation, the critical pump power and pump time of the control light are derived, respectively. It is found that with the increase of the frequency detuning of the incident light, the critical power of the control light will rise, while the corresponding critical time will be shortened. It is also revealed that under the same conditions, the critical total power of the multiple-beam control light is less than the one of the single-beam control light. The theoretical predictions show perfect agreement with the simulation results.

Ian S. Osborne