Abstract: A method is provided for identifying a contaminant in a gaseous space. The method includes: generating a broadband optical waveform; shaping the optical waveform to match an expected waveform for a known contaminant; and transmitting the shaped optical waveform towards an unknown contaminant. Upon receiving a reflected optical waveform from the unknown contaminant, determining whether the unknown contaminant correlates to the known contaminant based on the reflected waveform.

Abstract: A method is provided for identifying a contaminant in a gaseous space. The method includes: generating a broadband optical waveform; shaping the optical waveform to match an expected waveform for a known contaminant; and transmitting the shaped optical waveform towards an unknown contaminant. Upon receiving a reflected optical waveform from the unknown contaminant, determining whether the unknown contaminant correlates to the known contaminant based on the reflected waveform.

Abstract: A method of an apparatus for compensating optical non-linearity in optical devices and transmission systems. Two second order interactions are cascaded in phase-mismatched second harmonic generation to accumulate a non-linear phase shift of a fundamental wave. The non-linear phase shift can be set to provide a desired amount of non-linearity compensation. Compensation takes place in a compensating medium having a negative effective non-linear refractive index at the design operating conditions of the compensating medium. Compensators incorporating these principles may be incorporated as passive or active components in optical transmitters, repeaters or receivers. Active components may be tuned by varying the operating condition of the compensating medium, for example by controlling temperature or applied stress.