Photonic crystal waveguide based sensors

Waveguide based sensors allow independent control over sensitivity and dynamic range, which is not possible in resonance based sensors. In this paper, we present a refractive index sensor based on using photonic crystal waveguides (PCWs) in an unbalanced Mach-Zehnder interferometer configuration. In this configuration the dynamic range of the sensor is determined by the path difference between the two arms and the sensitivity is controlled by the length of the PCW. We show that by using PCWs we can get a factor of 8 improvement in sensitivity over a ridge-waveguide based sensor. This enhanced sensitivity is achieved due to reduced group velocity in a PCW. By reducing the loss at low group velocities the sensitivity can be further improved.

[1]  Xiaodong Yang,et al.  Enhanced stimulated Raman scattering in slow-light photonic crystal waveguides , 2006, QELS 2006.

[2]  Wei Jiang,et al.  Thermooptically Tuned Photonic Crystal Waveguide Silicon-on-Insulator Mach–Zehnder Interferometers , 2007, IEEE Photonics Technology Letters.

[3]  Toshihiko Baba,et al.  Large delay-bandwidth product and tuning of slow light pulse in photonic crystal coupled waveguide. , 2008, Optics express.

[4]  Gorachand Ghosh,et al.  Handbook of thermo-optic coefficients of optical materials with applications , 1998 .

[5]  T. Baba,et al.  Refractive index sensing utilizing a CW photonic crystal nanolaser and its array configuration , 2008 .

[6]  Martin Kristensen,et al.  Photonic-crystal waveguide biosensor. , 2007, Optics express.

[7]  Carlos Angulo Barrios,et al.  Optical Slot-Waveguide Based Biochemical Sensors , 2009, Sensors.

[8]  Ali Adibi,et al.  Wide bandwidth photonic crystal waveguide bends , 2010, OPTO.

[9]  Siva Yegnanarayanan,et al.  Efficient coupling of light into the planar photonic crystal waveguides in the slow group velocity regime , 2008, SPIE OPTO.

[10]  R. Baets,et al.  Silicon-on-Insulator microring resonator for sensitive and label-free biosensing. , 2007, Optics express.

[11]  G. M. Hale,et al.  Optical Constants of Water in the 200-nm to 200-microm Wavelength Region. , 1973, Applied optics.

[12]  D. Gill,et al.  Optical sensing of biomolecules using microring resonators , 2006, IEEE Journal of Selected Topics in Quantum Electronics.