This invention proposes the use of a nonlinear spectral broadening subsystem as a post-CPA pulse compression add-on for high energy laser systems. The proposed solution utilizes the beam profile of a high peak power laser as a reference to shape a highly transmissive nonlinear plastic (e.g., CR39) itself to ensure a spatially homogeneous nonlinear spectral broadening.
Image
This invention works by imaging an ultrafast pulse diffracted from a large grating onto a spatial light modulator (SLM) thereby directly transcribing an arbitrary record on a pulse front tilted (PFT) ultrafast pulse. The grating generates PFT of the input pulse, and the SLM provides temporal control of the pulse through the space-to-time mapping of the tilted pulse. Coupling this patterned…
Image
This invention exploits the non-linearities of optical Mach-Zehnder (MZ) electrooptic modulators to enhance small signal dynamic range at higher bandwidths. A linear photodiode (PD) converts the amplified optical signal output from the MZ back to an electrical signal completing an Electrical-Optical-Electrical (EOE) conversion cycle. The dynamic range can be further enhanced by daisy chaining…
Image
LLNL researchers has developed designs to augment WBG/UWBG-based OALVs to improve their power handling capability under CW operational environments. These designs include:
Image
Design and construction of a photoconductive switch requires a diamond photoconductor illuminated by light of a certain excitation wavelength. The diamond material is specifically doped with substitutional nitrogen, which act as a source of electrons. The device architecture allows maximum light entering the aperture. The top and bottom electrodes are made of ultra wide band gap (UWBG)…
Image
The approach is to use a custom-designed frustrum and attach it to the optical fiber that connects to the PCSS. Light from the fiber enters the frustrum, spreads out, and enters the PCSS. Any unabsorbed light re-enters the frustrum and, because of its geometry, reflects back into the PCSS itself with only a negligible fraction escaping from the fiber. The shape of the novel frustrum is…
Image
LLNL researchers in the NIF Directorate DoD Technologies RF Photonics Group explored phase modulation solutions to this signal processing challenge. Optical frequency combs offer phase noise characteristics that are orders of magnitude lower than available from commercial microwave references. The Photonics Group researchers recognized that by converting the intensity information into phase,…
Image
The SLIDER deflector includes a waveguide, a serrated mask positioned above the waveguide cladding, and a synchronized pump beam. The pump beam illuminates the serrated mask with a short pulse and transfers its pattern to the guiding layer where it imprints a sequence of prisms. The prisms are activated via nonlinear optical effects in the semiconductor and persist for the duration of the…
Image
The Optical Transconductance Varistor (OTV, formerly Opticondistor) overcomes depletion region voltage limitations by optically exciting wide bandgap materials in a compact package. A 100μm thick crystal could have the capability approaching 40kV and would replace numerous equivalent junction devices. Thus, unlike present junction transistors or diodes, this wide bandgap device can be stacked…