A novel miniature integrated-optical sensor for versatile multichannel applications is described. Wavelength-modulation techniques using laser diodes (vertical-cavity surface-emitting lasers) are used to interrogate multiple-waveguide sensing regions on a single integrated-optical chip for accurate measurement of effective refractive-index changes at a high data rate. With the experimental miniature sensor system, a resolution of Δ<i>N</i><sub>PP</sub> = 10<sup>-7</sup> (short term, peak to peak) of the effective refractive index was demonstrated. In terms of surface-mass coverage, this resolution corresponds to ΔΓ<sub>PP</sub> = 130 fg/mm<sup>2</sup>.
© 2000 Optical Society of America
(050.2770) Diffraction and gratings : Gratings
(130.2790) Integrated optics : Guided waves
(130.6010) Integrated optics : Sensors
(130.6750) Integrated optics : Systems
(140.3600) Lasers and laser optics : Lasers, tunable
M. Wiki and R. E. Kunz, "Wavelength-interrogated optical sensor for biochemical applications," Opt. Lett. 25, 463-465 (2000)