A tunable laser device based on silicon photonics includes a substrate configured with a patterned region comprising one or more vertical stoppers, an edge stopper facing a first direction, a first alignment feature structure formed in the patterned region along the first direction, and a bond pad disposed between the vertical stoppers. Additionally, the tunable laser includes an integrated coupler built in the substrate located at the edge stopper and a laser diode chip including a gain region covered by a P-type electrode and a second alignment feature structure formed beyond the P-type electrode. The laser diode chip is flipped to rest against the one or more vertical stoppers with the P-type electrode attached to the bond pad and the gain region coupled to the integrated coupler. Moreover, the tunable laser includes a tuning filter fabricated in the substrate and coupled via a wire waveguide to the integrated coupler.

A tunable laser device based on silicon photonics includes a substrate configured with a patterned region comprising one or more vertical stoppers, an edge stopper facing a first direction, a first alignment feature structure formed in the patterned region along the first direction, and a bond pad disposed between the vertical stoppers. Additionally, the tunable laser includes an integrated coupler built in the substrate located at the edge stopper and a laser diode chip including a gain region covered by a P-type electrode and a second alignment feature structure formed beyond the P-type electrode. The laser diode chip is flipped to rest against the one or more vertical stoppers with the P-type electrode attached to the bond pad and the gain region coupled to the integrated coupler. Moreover, the tunable laser includes a tuning filter fabricated in the substrate and coupled via a wire waveguide to the integrated coupler.

A method for increasing the MeV hot electron yield and secondary radiation produced by short-pulse laser-target interactions with an appropriately high or low atomic number (Z) target. Secondary radiation, such as MeV x-rays, gamma-rays, protons, ions, neutrons, positrons and electromagnetic radiation in the microwave to sub-mm region, can be used, e.g., for the flash radiography of dense objects.

Embodiments of the invention describe polarization insensitive optical devices utilizing polarization sensitive components. Light comprising at least one polarization state is received, and embodiments of the invention select a first optical path for light comprising a first polarization state or a second optical path for light comprising a second polarization state orthogonal to the first polarization state. The optical paths include components to at least amplify and/or modulate light comprising the first polarization state; the second optical path includes a polarization rotator to rotate light comprising the second polarization state to the first polarization state. Embodiments of the invention further describe optical devices including a polarization mode converter to convert light comprising a first and a second polarization state to light comprising different spatial modes of the first polarization state; light comprising the different spatial modes of the first polarization state is subsequently amplified and modulated.

Embodiments of the invention describe polarization insensitive optical devices utilizing polarization sensitive components. Light comprising at least one polarization state is received, and embodiments of the invention select a first optical path for light comprising a first polarization state or a second optical path for light comprising a second polarization state orthogonal to the first polarization state. The optical paths include components to at least amplify and/or modulate light comprising the first polarization state; the second optical path includes a polarization rotator to rotate light comprising the second polarization state to the first polarization state. Embodiments of the invention further describe optical devices including a polarization mode converter to convert light comprising a first and a second polarization state to light comprising different spatial modes of the first polarization state; light comprising the different spatial modes of the first polarization state is subsequently amplified and modulated.

The present disclosure discloses a narrow-linewidth laser. The narrow-linewidth laser comprises a passive ring waveguide, a first passive input/output waveguide which is coupled with the passive ring waveguide, a gain wavelength-selection unit which is used for providing gain for the whole laser and is configured to be capable of selecting the light with a specific wavelength to be coupled into the passive ring waveguide, and a second passive input/output waveguide which is coupled with the passive ring waveguide in order to output lasing light from the laser. The narrow-linewidth semiconductor laser provided by the present disclosure has a simple structure and does not have butt-joint coupling loss between a gain region and a waveguide external cavity region. There is no a linewidth limitation caused by butt-coupling loss in such semiconductor lasers. Moreover, because of the integral formation semiconductor technique, the laser should have low cost, higher stability and reliability, and higher resistance to severe environment. Furthermore, based on a loss compensation structure, a ring external cavity of the laser can work in a critical coupling state under different coupling coefficients. Therefore, the laser with a narrow linewidth and a high side-mode suppression ratio should be achieved.

Conventional integrated optical amplifiers, which combine different types of platforms, e.g. silicon photonic integrated circuit for the device layer, and a Group III-V material for the gain medium, typically include a curved waveguide extending through the gain medium coupled to waveguides in the main device layer. Unfortunately, the radius of curvature of the curved waveguide becomes a limiting factor for both size and amplification. Accordingly, an optical amplifier which eliminates the need for the curved waveguide by including a coupler for splitting an input optical signal into two sub-beams, for passage through the gain medium, and a reflector for reflecting the two sub-beams back through the gain medium to the coupler for recombination, would be a welcome improvement. A phase tuner may also be provided to ensure coherence cancellation between the two sub-beams to maximize output and minimize back reflection without requiring an isolator.

A novel broadband light source composed of supercontinuum light source and high-power single-wavelength semiconductor laser diodes. It includes an electronics control board, a supercontinuum light source, and a series of single-wavelength semiconductor laser diodes. The frequency of each single-wavelength semiconductor laser diodes is adjusted to integer times or division times of a frequency of the supercontinuum light source by using the electronics control board. Weaknesses of the supercontinuum light source that it is difficult to cover a wavelength less than 400 nm and power density at a wavelength of 400-2400 nm is less than 10 mW/nm are compensated by using the single-wavelength semiconductor lasers. Wavelengths of the single-wavelength semiconductor laser diodes can cover 375-2400 nm, and the highest power density can reach 200 mW/nm, so that the novel broadband light source composed by the single-wavelength semiconductor laser diodes is applicable to a field such as spectral microscopy in a range of 375-400 nm. In addition, by means of electronics clock control on the single-wavelength semiconductor laser diodes and a pulse generation circuit of the supercontinuum light source, same-phase output of the single-wavelength semiconductor laser diodes and the supercontinuum light source can be kept, and relative pulse delays are flexible and adjustable.

An optical amplifier includes a polarization splitter, a polarization rotator, first and second optical couplers, and first and second semiconductor optical amplifying devices. The TE polarized wave of light split by the polarization splitter is input to a first input port of the first optical coupler. The TM polarized wave of the split light is converted into a TE polarized wave by the polarization rotator to be input to a second input port of the first optical coupler. First light and second light output from a first output port and a second output port of the first optical coupler are amplified by the first semiconductor optical amplifying device and the second semiconductor optical amplifying device to be input to a first input port and a second input port of the second optical coupler, respectively. Third light is output from an output port of the second optical coupler.

A novel broadband light source composed of supercontinuum light source and high-power single-wavelength semiconductor laser diodes. It includes an electronics control board, a supercontinuum light source, and a series of single-wavelength semiconductor laser diodes. The frequency of each single-wavelength semiconductor laser diodes is adjusted to integer times or division times of a frequency of the supercontinuum light source by using the electronics control board. Weaknesses of the supercontinuum light source that it is difficult to cover a wavelength less than 400 nm and power density at a wavelength of 400-2400 nm is less than 10 mW/nm are compensated by using the single-wavelength semiconductor lasers. Wavelengths of the single-wavelength semiconductor laser diodes can cover 375-2400 nm, and the highest power density can reach 200 mW/nm, so that the novel broadband light source composed by the single-wavelength semiconductor laser diodes is applicable to a field such as spectral microscopy in a range of 375-400 nm. In addition, by means of electronics clock control on the single-wavelength semiconductor laser diodes and a pulse generation circuit of the supercontinuum light source, same-phase output of the single-wavelength semiconductor laser diodes and the supercontinuum light source can be kept, and relative pulse delays are flexible and adjustable.