A shaping encoder capable of improving the performance of PCS in nonlinear optical channels by performing the shaping in two or more stages. In an example embodiment, a first stage employs a shaping code of a relatively short block length, which is typically beneficial for nonlinear optical channels but may cause a significant penalty in the energy efficiency. A second stage then employs a shaping code of a much larger block length, which significantly reduces or erases the penalty associated with the short block length of the first stage while providing an additional benefit of good performance in substantially linear optical channels. In at least some embodiments, the shaping encoder may have relatively low circuit-implementation complexity and/or relatively low cost and provide relatively high energy efficiency and relatively high shaping gain for a variety of optical channels, including but not limited to the legacy dispersion-managed fiber-optic links.

A fully programmable laser field shaping apparatus that can configure a beam of laser pulses in both shape and time to generate laser pulses with varying spatio-temporal profiles for adaptive nonlinear optical propagation. The laser field shaping scheme in accordance with the present invention, Adaptive Spatio-Temporal Optical Pulse Shaper (A-STOPS), utilizes dispersive elements and a programmable spatial varying optical element (e.g. deformable mirror, spatial light modulator, etc.) to impose spatial variations on each frequency component of a laser pulse. Each frequency component maps directly to a temporal slice within a chirped laser pulse. The result is the ability to generate complex spatio-temporal variation on a laser pulse with wide ranging applications in linear and nonlinear optics.

A device for processing an input light beam comprising at least one optical pulse having an original duration, forms the input light beam into a predetermined shape. The device comprises an optical input; a stretching device, with a view to temporally elongating the duration of the optical pulse and thus transmitting a temporally stretched radiation; a compressing device, with a view to at least partially restoring the original duration of the optical pulse; and an optical output. The processing device also comprises a shaping device comprising at least one multi-plane converter placed upstream of the compressing device, which is configured to process the temporally stretched radiation with a view to forming the output beam into the predetermined shape.

Disclosed is a femtosecond laser device. The femtosecond laser device includes a pulse oscillator configured to generate a laser pulse, a pulse width stretcher configured to stretch a width of the laser pulse, a pulse width compressor connected to the pulse width stretcher to compress the width of the laser pulse, a pulse amplifier disposed between the pulse width compressor and the pulse width stretcher to amplifier an intensity of the laser pulse, and a nonlinear pulse attenuator including an optical fiber connected between the pulse width amplifier and the pulse width stretcher and deformed to have a spiral shape, a stretched length, or a twist.

A receiving device includes a light source outputting local oscillation light, a detector detecting intermittent input of a burst light signal by using the local oscillation light, a first converter converting the detected burst optical signal into an electrical analog signal, an amplifier amplifying the analog signal according to a gain, a second converter converting the amplified analog signal into a digital signal, and a setting processor setting the gain of the amplifier and a wavelength of the local oscillation light instructed by a control device when setting a communication line with one of transmitting devices transmitting the burst optical signal, wherein, before setting the communication line, the setting processor switches the wavelength of the local oscillation light according to the burst optical signal transmitted from each of the transmitting devices, adjusts the gain of the amplifier and notifies the control device of the adjusted gain.

A laser system and method include a self-referencing shaper. A self-referencing pulse shaper is provided in an embodiment. Another aspect of a laser system includes at least one beam splitter splitting a reference beam from a working beam and a test beam, a delay optic delaying a reference laser beam, an active shaper, an interferometer, and a programmable controller. In another aspect, a method includes splitting an input laser pulse into a reference pulse and a shaping pulse, controlling phase and amplitude of the shaping pulse with an adjustable pulse shaper, creating an optical delay of the reference pulse, comparing a test pulse and the reference pulse after the controlling and delay, the laser system characterizing the input laser pulse and monitoring the laser system's own dispersion in a self-referenced manner, and correcting an output working laser pulse by adjusting the pulse shaper based on the comparing step.

A method includes: producing a light beam made up of pulses having a wavelength in the deep ultraviolet range, each pulse having a first temporal coherence defined by a first temporal coherence length and each pulse being defined by a pulse duration; for one or more pulses, modulating the optical phase over the pulse duration of the pulse to produce a modified pulse having a second temporal coherence defined by a second temporal coherence length that is less than the first temporal coherence length of the pulse; forming a light beam of pulses at least from the modified pulses; and directing the formed light beam of pulses toward a substrate within a lithography exposure apparatus.

A method for driving an acousto-optic element with an acousto-optic crystal and a piezoelectric transducer for setting the acousto-optic crystal in mechanical vibration includes driving the piezoelectric transducer with a drive signal with at least one drive frequency. The at least one drive frequency in alternation takes on a plurality of different values around a center frequency during a passage of a mechanical vibrational wave through the acousto-optic crystal, such that a grating that is produced owing to density fluctuations in the acousto-optic crystal exhibits different grating spacings at the same time.

The laser doping apparatus may irradiate a predetermined region of a semiconductor material with a pulse laser beam to perform doping. The laser doping apparatus may include: a solution supplying system configured to supply dopant-containing solution to the predetermined region, and a laser system including at least one laser device configured to output the pulse laser beam to be transmitted by the dopant-containing solution, and a time-domain pulse waveform changing apparatus configured to control a time-domain pulse waveform of the pulse laser beam.

Apparatus and methods for forming fine scale structures (4, 4′, 4″, 5, 6, 7, 8) in the surface of a dielectric substrate (3) to two or more depths are disclosed. In an example, the apparatus comprises a first solid state laser (12) arranged to provide a first pulsed laser beam (13), a first mask (16) having a pattern for defining a first set of structures (4, 6, 7, 8) at a first depth, a projection lens (17) for forming a reduced size image of said pattern on the surface (3) of the substrate and a beam scanner arranged to scan said first pulsed laser beam (13) in a two-dimensional raster scan relative to the first pattern to form a first set of structures (4, 6, 7, 5) at a first depth in the substrate, wherein the first or a further solid state laser is arranged to form a second set of structures (8) at a second depth in the substrate (3).