Photochemistry in photonic crystal fibers

Photonic crystal fiber (PCF) has proven very useful for enhancing light-matter interactions, offering interaction lengths much longer than those available using conventional techniques. A well-defined optical mode propagating through a microfluidic channel or gas cell offers a unique way of carrying out absorption spectroscopy in very small sample volumes (∼1 µL) [1–3]. Additional advantages of PCF include its flexibility and the opportunity for system miniaturization. In this paper, we demonstrate the use of hollow-core photonic crystal fiber (HC-PCF) as a highly-controlled (photo)chemical microreactor in which reaction dynamics can be monitored in real-time via broadband spectroscopy. Strong confinement of both sample and light in the core region results in enhanced reaction dynamics and strongly reduced laser power requirements.