Abstract: A device includes a first mode converter and a second mode converter that define a region between the first mode converter and the second mode converter. The region can contain a plurality of optical modes including at least three modes. The first mode converter and the second mode converter can generate a near-field via a conversion between the plurality of optical modes. The first mode converter can receive an input wave of a first mode and the second mode converter can generate an output wave of a second mode different from the first mode. The first mode converter and the second mode converter can generate a confined near-field via a conversion between the plurality of optical modes.

Abstract: A laser device includes a gain medium including a facet. The laser device includes a metasurface including a plurality of supercells. The metasurface is disposed on a substrate and configured to reflect and focus a first portion of light from the facet back to the gain medium as a feedback beam. The metasurface can be configured to reflect a second portion of the light as an output beam at an angle that is nonzero relative to a direction of the feedback beam. The metasurface can be configured to transmit a second portion of the light as an output beam through the metasurface away from the facet. The emission wavelength of the laser device can be tuned by translating the metasurface. The output beam can be collimated towards a fixed direction while tuning the wavelength.

Abstract: A device includes a first mode converter and a second mode converter that define a region between the first mode converter and the second mode converter. The region can contain a plurality of orthogonal modes of a wave. The wave, when sent from outside the region and when propagating from the first mode converter towards the second mode converter, can include a first mode of the plurality of orthogonal modes. The second mode converter can convert the wave from the first mode of the plurality of orthogonal modes, to a second mode of the plurality of orthogonal modes that is different from the first mode. The first mode converter can convert the wave to the first mode of the plurality of orthogonal modes.

Abstract: A laser device includes a gain medium including a facet. The laser device includes a metasurface including a plurality of supercells. The metasurface is disposed on a substrate and configured to reflect and focus a first portion of light from the facet back to the gain medium as a feedback beam. The metasurface can be configured to reflect a second portion of the light as an output beam at an angle that is nonzero relative to a direction of the feedback beam. The metasurface can be configured to transmit a second portion of the light as an output beam through the metasurface away from the facet. The emission wavelength of the laser device can be tuned by translating the metasurface. The output beam can be collimated towards a fixed direction while tuning the wavelength.

Abstract: Disclosed is a laser system including a first laser and a second laser. The first laser includes a laser cavity, and a gas phase molecular gain medium disposed in the laser cavity, the gain medium having an absorption band. The second laser is a solid state laser configured to be continuously tunable, with respect to an emission wavelength of the second laser, over the absorption band of the gain medium, and the second laser is tuned to pump rotational vibrational transitions in the gain medium to achieve a rotational population inversion.

Abstract: A wireless communication device includes a quantum cascade laser (QCL) configured to generate a terahertz (THz) or microwave carrier signal. The QCL includes a laser waveguide, a laser optical gain medium incorporated in the laser waveguide, and at least one electrode. An antenna may be integrated with the electrode. The device may be a transmitter, the electrode configured to receive an input baseband signal, the QCL configured to couple the THz or microwave carrier signal and the input baseband signal into a THz or microwave communication signal, and the antenna configured to transmit the THz or microwave communication signal. The device may be a receiver, the antenna configured to receive a THz or microwave communication signal, and the QCL configured to de-couple the THz or microwave communication signal from the THz or microwave carrier signal into an output baseband signal.

Abstract: A wireless communication device includes a quantum cascade laser (QCL) configured to generate a terahertz (THz) or microwave carrier signal. The QCL includes a laser waveguide, a laser optical gain medium incorporated in the laser waveguide, and at least one electrode. An antenna may be integrated with the electrode. The device may be a transmitter, the electrode configured to receive an input baseband signal, the QCL configured to couple the THz or microwave carrier signal and the input baseband signal into a THz or microwave communication signal, and the antenna configured to transmit the THz or microwave communication signal. The device may be a receiver, the antenna configured to receive a THz or microwave communication signal, and the QCL configured to de-couple the THz or microwave communication signal from the THz or microwave carrier signal into an output baseband signal.