| Optical spectrometers have a wide variety of applications some of them being bio/chemical sensors, space applications, fluorescence spectroscopy, absorption and emission spectroscopy, environmental monitoring, military applications, remote sensing, medical diagnosis, diamond grading etc. Compact, light-weight, rigid miniature spectrometers with no moving parts are needed for a wide variety of applications including bio-sensors and space applications where every inch of payload counts. Miniaturization increases portability and paves way for making in-situ measurements.; There is an increasing need today not only for compact, hand-held miniature designs but also for ones with high resolution. The performance of a spectrometer is better if its resolution is higher. In biosensors and chemical sensors, the sensitivity of the device is higher if the spectrometer has a higher resolution. We have proposed to achieve a better resolution than the existing designs in a wider spectral range while still retaining the compactness by introducing a novel concept which is a combination of 2-D geometry and 3-D geometry---a combination of integrated optics and micro-optics. We have successfully demonstrated two prototypes---one in a size of a cubic cm and the other, a cubic mm. We have demonstrated a resolution of 0.3 nm to 4.6 nm in a spectral range of 194 nm with a spectrometer optical part size of below 0.2 cubic cm and a 2 nm FWHM for the size of the spectrometer optical part below 0.01 cubic mm. |
