With the trend to increasingly faster processes, there is a growing demand for generation of optical arbitrary waveforms with ~1 ps resolution and long records. No arbitrary waveform generators currently exist that can achieve this resolution over long record lengths.
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 pulse into a single mode system collapses the PFT record into a single-moded coherent beam of light. Choosing the single-moded system to be a regenerative amplifier or optical fiber amplifier results in a mechanism to amplify this weakly coupled pulse to practical energy levels with low noise.
Publications:
D. E. Mittelberger, R. D. Muir, M. Y. Hamamoto, M. A. Prantil, and J. E. Heebner, "Frequency-to-time optical arbitrary waveform generator," Opt. Lett. 44, 2019, 2863-2866 (https://doi.org/10.1364/OL.44.002863)
D. E. Mittelberger, R. Muir, M. Hamamoto, M. Prantil and J. Heebner, "Arbitrary Optical Waveform Generation by Nonlinear Frequency-to-Time Conversion," 2019 Conference on Lasers and Electro-Optics (CLEO), San Jose, CA, USA, 2019, pp. 1-2 (https://doi.org/10.1364/CLEO_SI.2019.SM4O.3)
- Allows long record lengths (nanoseconds) while retaining high resolution (picosecond) without trading amplitude resolution, and hence dynamic range, for temporal resolution as occurs in traditional electronic approaches.
- Allows direct patterning in the time domain as opposed to other approaches that pattern in the Fourier domain.
- Utilizes a simple optical design that lends itself to integration with ultrafast lasers typically used to excite transient signals and works directly with optical signals (no need to convert to an electrical signal).
- Not susceptible to wavelength drift due to timing jitter in an Optical Parametric Amplifier (OPA).
- Doesn’t require complex nonlinear optics thus avoiding noise and instabilities associated with nonlinear elements.
- Can potentially stitch together even longer records with a Hyper Mach-Zehnder Interferometer (HMZI).
Optical arbitrary waveform generation for wide bandwidth telecommunications and next generation additive manufacturing.
Current stage of technology development: TRL 3-4
LLNL has patent(s) on this invention.
U.S. Patent No. 11,715,924 Space-Time Induced Linearly Encoded Transcription for Temporal Optimization (STILETTO) published 8/1/2023