Abstract: Techniques for generating an arbitrary target electromagnetic signal with a nonlinear material, include determining a time varying target amplitude and target phase and an order n of a nonlinear material. For each time, a first set of nth roots of the target amplitude and a second set of nth roots of the target phase are determined. An input amplitude based on one value from the first set and an input phase based on one value from the second set is determined at each time. A difference between temporally successive values of phase is minimized. An electromagnetic signal is modulated to impose the input amplitude and phase to produce a modulated electromagnetic input signal that is introduced into the nonlinear material to produce a target electromagnetic signal.

Abstract: Techniques for generating an arbitrary target electromagnetic signal with a nonlinear material, include determining a time varying target amplitude and target phase and an order n of a nonlinear material. For each time, a first set of nth roots of the target amplitude and a second set of nth roots of the target phase are determined. An input amplitude based on one value from the first set and an input phase based on one value from the second set is determined at each time. A difference between temporally successive values of phase is minimized. An electromagnetic signal is modulated to impose the input amplitude and phase to produce a modulated electromagnetic input signal that is introduced into the nonlinear material to produce a target electromagnetic signal.

Abstract: Techniques for spatial spectral holography include a doped crystal comprising Thulium doped into a host crystal of Yttrium Lutetium Aluminum Garnet wherein a concentration of Thulium atoms is less than 3 atomic percent. Techniques further include an apparatus with a source for optical electromagnetic radiation and a cryocooler configured to maintain an operating temperature in a range from about 3 Kelvin to about 6 Kelvin. The cryocooler includes a first optical window. The apparatus also includes a doped crystal comprising Thulium doped into a host crystal of Yttrium Lutetium Aluminum Garnet disposed inside the cryocooler in a position to be illuminated by incident optical electromagnetic radiation derived from the source. The apparatus also includes a detector configured to detect optical electromagnetic radiation emitted from the doped crystal. Techniques include a method for using at least one of the above doped crystals.

Abstract: An apparatus includes a single or dual output port, dual-drive Mach-Zehnder Interferometer configured to generate a first optical signal in one path, and to generate a second optical signal in a different path. The apparatus also includes an optical spectrum analyzer configured to receive output from at least one port of the dual-drive Mach-Zehnder Interferometer. A method includes causing radio frequency signals from two different antennae to modulate an optical carrier at a corresponding drive of a dual-drive Mach-Zehnder Interferometer, and causing output from at least one port of the Mach-Zehnder Interferometer to be directed to an optical spectrum analyzer. The method further comprises determining arrival angle at each of a plurality of frequencies in the radio frequency signals based on output from the optical spectrum analyzer.