A system and method that may enable the generation of highly-efficient, high-power, narrow-linewidth, and tunable light sources from microwave frequencies to mid-infrared wavelengths is disclosed. The light source comprises a nonlinear medium coupled to a multi-modal cavity and a high-energy pump source. The nonlinear medium provides three-wave mixing between modes present in the cavity to generate, for example, terahertz waves. The broadband cavity enables cascading nonlinear processes. By engineering the Q-factors of the cavity's many modes, red-shifted (stokes) cascaded nonlinear processes strongly dominate over their blue-shifted (anti-stokes) counterparts, resulting in a quasi-complete depletion of the pump energy into the THz mode.

Transducers and methods of making the same include a substrate having a cavity with a diameter that supports whispering gallery modes at a frequency of an input signal. A focusing structure in the cavity focuses the electric field of the input signal. A resonator directly under the focusing structure has a crystalline structure that generates an electro-optic effect when exposed to electrical fields. An electric field of the input signal modulates an output signal in the resonator via the electro-optic effect.

Embodiments of the invention disclose a display device, comprising a substrate, a plurality of pixels on the substrate and a backlight module located at a side of the substrate away from the pixels. Each pixel has a microcavity structure, in which the light emitted from the backlight module oscillates many times and exits as visible light of at least three colors, thereby enabling the display device to realize color display. Compared to the existing liquid crystal display device, this display device will not be limited by the manufacturing process when it is applied in the flexible display field. Compared to the existing organic electroluminescent display device, this display device will not have the problems of low yield, high cost and short life time, etc.

A digital light path length modulator comprises an optical path length extender (OPLE) and a polarization modulator. The OPLE comprises two light paths having different path lengths, such that light having a first polarization is directed through a first light path, and the light having a second polarization is directed through a second light path.

Transducers and methods of making the same include a substrate having a cavity with a diameter that supports whispering gallery modes at a frequency of an input signal. A focusing structure in the cavity focuses the electric field of the input signal. A resonator directly under the focusing structure has a crystalline structure that generates an electro-optic effect when exposed to electrical fields. An electric field of the input signal modulates an output signal in the resonator via the electro-optic effect.

A system includes an optical parametric oscillator (OPO) device. The OPO device has an optical resonator, a first nonlinear optical element (NLO) and a second non-linear optical element (NLO). The first NLO can produce, via OPO of a first pump beam, a first output with a first frequency and a second output with a second frequency. The second frequency is lower than the first frequency. The second NLO can produce, via OPO of a second pump beam (with a higher frequency than the first), a third output with a third frequency and a fourth output with a fourth frequency. The fourth frequency is lower than the third frequency. The first frequency is the same, or at least substantially the same, as the fourth frequency. The OPO device is configured to resonate at the first frequency and the fourth frequency.

A device for a nonlinear optical frequency-conversion of laser radiation comprises a multipass arrangement being arranged such that a laser radiation coupled into the multipass arrangement carries out multiple roundtrips in the multipass arrangement. The device further comprises a nonlinear optical medium-arranged at least partly within the multipass arrangement such that at least in several of the roundtrips the laser radiation coupled into the multipass arrangement passes through the nonlinear optical medium to carry out a nonlinear optical conversion of a part of the laser radiation propagating through the nonlinear optical medium into frequency-converted components based on a second order susceptibility .sup.(2) of the nonlinear optical medium. The device is configured such that the laser radiation- and the frequency-converted components propagate in the multipass arrangement-along a common beam path including at least five passes through the nonlinear optical medium.

Transducers and methods of making the same include a substrate having a cavity with a diameter that supports whispering gallery modes at a frequency of an input signal. A focusing structure in the cavity focuses the electric field of the input signal. A resonator directly under the focusing structure has a crystalline structure that generates an electro-optic effect when exposed to electrical fields. An electric field of the input signal modulates an output signal in the resonator via the electro-optic effect.

A method and an arrangement of spectrally broadening laser pulses for non-linear pulse compression is disclosed which is based on the transition from the spectral broadening in a waveguide to the spectral broadening in a suitably shaped lens conductor. The arrangement is non-sensitive with respect to the variations of the pulse power, the position and parameters of the laser beam. The spectrally broadened pulses can be compressed in a satisfactory manner and the quality of the laser beam maintained by dividing the non-linear phase required for spectral broadening into sufficiently smaller steps which can be separated without non-linearity by suitable prorogation. The limitation of the pulse powers to less than the critical power of dielectrics is thus overcome and a pulse energy range for which the spectral broadening in the glass fibers cannot be used, is developed. The arrangement can compress pulses having a large average power.

Transducers and methods of making the same include a substrate having a cavity with a diameter that supports whispering gallery modes at a frequency of an input signal. A focusing structure in the cavity focuses the electric field of the input signal. A resonator directly under the focusing structure has a crystalline structure that generates an electro-optic effect when exposed to electrical fields. An electric field of the input signal modulates an output signal in the resonator via the electro-optic effect.