Abstract

Optofluidic biolasers are recently being considered in bioanalytical applications due to their advantages over the conventional biosensing methods Exploiting a photonic crystal slab with selectively dye-infiltrated air holes, we propose a new optofluidic heterostructure biolaser, with a power conversion efficiency of 25% and the spectral linewidth of 0.24 nm. Simulations show that in addition to these satisfactory lasing characteristics, the proposed lab-on-a-chip biolaser is highly sensitive to the minute biological changes that may occur in its cavity and can detect a single virus with a radius as small as 13 nm.

Nanophotonics merged with microfluidics− i.e., optofluidics− offers a new way of implementing miniaturized optoelectronic devicesthat can be intrinsically adaptive and reconfigurable. Unique properties of liquids, such asthe potential of integration in lab-on-a-chip systems and compatibility with microfluidic components make optofluidic systems highly competitive in the development of biophotonics. Moreover, most of the biochemical reactions should be reproduced in a fluid, making optofluidic system substantially advantageousin biological sensing applications. A novel emerging device in this area is the optofluidic biolaser that can measure changes in biological molecules precisely. When biochemical or biological molecules are incorporated into a gain medium a new class of laser known as the optofluidic biolaser can emerge [1]. A number of optofluidic biosensors based on different principles with diverse advantages, drawbacks, sensitivities, and detection limits, are developed in research and commercial products[2-7]. Among passive sensors, those based on photonic crystals(PhCs) [2-4] or ring resonators [7]show satisfactory sensing signal. However, other types of passive biosensors may experience weak sensing signal and broad spectrum [1].