Shock-Wave Modulation and Control of Electromagnetic Radiation

Applications

Electromagnetic modulation and control are useful in telecommunications, signal processing, power electronics and solar cells.

Problem Addressed

Photonic crystals are a promising and versatile way to control the propagation of electromagnetic radiation. However, very little attention has been given to effects of non-stationary photonic crystals on electromagnetic radiation propagation.

Technology

The invented device converts electromagnetic radiation from one frequency to another with use of a moving grating made of a nonlinear medium. Light is input into the medium at one frequency and extracted at a second frequency. This effect is achieved with electromagnetic propagation in a shocked photonic crystal. While a significant change in light frequency would usually require interactions with objects moving at a significant fraction of the speed of light, this approach allows frequency conversion at arbitrarily slow speeds. The amount of frequency shift can be tuned by adjusting the size of the bandgap of the pre-shocked crystal. By tuning the system to match this frequency change, a 100% conversion efficiency can be achieved. This system can also classically decrease the bandwidth of a propagating signal to a single frequency. With the inclusion of defects in the photonic crystal, light can be trapped in a defect state at the shock front for a controlled period of time.

Advantages

  • Grants controlled pulse delays on electromagnetic radiation with the inclusion of defects
  • Achieves 100% energy conversion in the right conditions
  • Capacity to convert broad bandwidth of frequencies to a nearly single frequency