An optical sensing system including an optical interrogator is operative with an array of reflective sensors, each sensor providing a separable reflected spectral response parameter such as a unique Gaussian standard deviation or reflected response compared to other sensors in the same operating wavelength range. The optical interrogator provides narrowband swept or broadband continuous optical power source to the array of FBG sensors, and an optical interrogator generates a g(x) representation of power vs wavelength of the reflected optical power and decomposes the representation into the wavelength of the individual sensors, thereby allowing operation of two or more FBG sensors in the same operating wavelength range.