Abstract: An antenna device for performing off-chip light coupling comprising an array of radiating elements whose thickness is larger than ?/2, the radiating elements being chosen such that the length of the array is smaller than 10?, where ? is the wavelength of light in the material chosen for the radiating elements. An advantage of this method is that, unlike in conventional waveguide grating antenna, by reducing the number of the radiating elements in the array, the dependence of the off-chip emission angle on the wavelength of light can be greatly reduced. Another advantage is that by using thick radiating elements the antenna efficiency can be greatly enhanced, thereby compensating for the reduced efficiency occurring as a consequence of using only a small number of radiating elements in the array.

Abstract: A method for detecting and identifying a remote gas, the method comprising the steps of: receiving a light wave associated with the remote gas; coupling the light wave into a single mode fibre; transmitting the light wave via the single mode fibre into a filter comprising a fibre-based tunable cavity; modulating the cavity length of the filter transmission window to cause a detected modulated signal that is proportional to the spectral feature; and processing the signal using a lock-in amplifier capable of low-pass filtering and out-of-frequency noise rejection.

Abstract: An integrated optical sensor enables the detection and identification of one or more remote gases using a transmission filter that matches specific absorption features of a remote gas and is detected using a single photodetection element. The sensor comprises an integrated optical component that is characterized by its transmission spectrum which corresponds to absorption or emission features of a target gas over a defined spectral bandpass, and the ability to have a reversibly tunable transmission spectrum. The change in the optical power output from the sensor as the transmission spectrum is tuned is proportional to the optical depth of the target gas absorption lines when viewed with a background light source. The optical power output from the integrated optical component is therefore related to the absorption spectrum of the input light Physical properties of the sensor are tailored to produce a quasi-periodic transmission spectrum that results in a stronger signal contrast for a specific gas.

Abstract: An integrated optical sensor enables the detection and identification of one or more remote gases using a transmission filter that matches specific absorption features of a remote gas and is detected using a single photodetection element. The sensor comprises an integrated optical component that is characterized by its transmission spectrum which corresponds to absorption or emission features of a target gas over a defined spectral bandpass, and the ability to have a reversibly tunable transmission spectrum. The change in the optical power output from the sensor as the transmission spectrum is tuned is proportional to the optical depth of the target gas absorption lines when viewed with a background light source. The optical power output from the integrated optical component is therefore related to the absorption spectrum of the input light Physical properties of the sensor are tailored to produce a quasi-periodic transmission spectrum that results in a stronger signal contrast for a specific gas.