Abstract: A device and method for producing a third harmonic signal from an optical pulse of wavelength k. In the device and method, an optical pulse at a wavelength k is incident on a material including at least one molecule having a formula D-U-A, where D is an electron donor group, A is an electron acceptor group, and ? is a conjugated structure having it bonds that connect D to A. The molecule exhibits a strong absorption band centered at a wavelengthko and a weakly absorbing region centered at a wavelength k, which is less than Xo. A wavelength k/2 has a value of about Xo, and a wavelength k/3 has a value of about X1. A third harmonic signal at k/3 is generated. From a measured third harmonic signal as a function of a time delay for separate optical pulses entering the material, at least one of a pulse width and a pulse shape of the optical pulse can be extracted. From a spectrally resolved third harmonic signal, a phase of the optical pulse can be extracted.

Abstract: An imaging system and method for imaging an object, where an objective lens directs light to the object, a coupling lens receives light reflected from a surface of the object and transmitted through the objective lens, and focuses the reflected light as an image of the object, and an annular light emitter arranged concentrically with an optical axis of the objective lens and the coupling lens emits to the objective lens the light directed to the object.