Trenton Berg

Ultrabroadband optical chirp linearization for precision metrology applications

We demonstrate precise linearization of ultrabroadband laser frequency chirps via a fiber-based self-heterodyne technique to enable extremely high-resolution, frequency-modulated cw laser-radar (LADAR) and a wide range of other metrology applications. Our frequency chirps cover bandwidths up to nearly 5 THz with frequency errors as low as 170 kHz, relative to linearity. We show that this performance enables 31-mum transform-limited LADAR range resolution (FWHM) and 86 nm range precisions over a 1.5 m range baseline. Much longer range baselines are possible but are limited by atmospheric turbulence and fiber dispersion.

Demonstrations of analog-to-digital conversion using a frequency domain stretched processor

Proof-of-concept analog-to-digital conversion demonstrations are presented for a photonics based frequency-domain, stretched processor. Here 800 MHz bandwidths and >26 dB dynamic range are shown, with models suggesting 10-bit performance over 20 GHz bandwidths.

Linearization of ultra-broadband optical chirps for precision length metrology

We demonstrate precise active linearization of ultra-broadband (>5 THz) laser frequency sweeps using a self-heterodyne technique. Frequency errors less than 170 kHz relative to linearity were observed enabling very high resolution ranging over large distances.

Imaging through obscurants with a heterodyne detection-based ladar system

Bridger Photonics has been researching and developing a ladar system based on heterodyne detection for imaging through brownout and other DVEs. There are several advantages that an FMCW ladar system provides compared to direct detect pulsed time-of-flight systems including: 1) Higher average powers, 2) Single photon sensitive while remaining tolerant to strong return signals, 3) Doppler sensitivity for clutter removal, and 4) More flexible system for sensing during various stages of flight. In this paper, we provide a review of our sensor, discuss lessons learned during various DVE tests, and show our latest 3D imagery.

Mid-Infrared Laser Source For Long-Range Range-Resolved Remote Monitoring of CO 2

We report a sub-10-ns, > 1 mJ mid-infrared laser at 2.0 ?m for remote sensing and range resolved concentration mappings of carbon dioxide. The source will enable meter-level CO2measurements from 100-meter distances.

Extremely High-Resolution LADAR System for Precision Length Metrology and Imaging

We report a precision LADAR system that can achieve 35 µm FWHM range-peak-width resolution and 86 nm range precisions for absolute distance and length metrology and precision 3-D LADAR imaging applications.

Real-Time Range-Doppler Radar Imaging Using a Coherent Holographic Analog Optical Signal Processor

A range-Doppler radar signal processor based upon coherent holographic analog optical signal processing is discussed. Advantages over conventional range-Doppler processors include increased bandwidths (>30 GHz), enhanced dynamic range, and ability to process any waveform type.

High-Resolution Range and Doppler LADAR Using Broadband Coherent Optical Processing

We demonstrate sub-nanosecond range and sub-50-Hz Doppler resolved LADAR measurements using spatial-spectral holographic processing in rare-earth ion doped crystals. Our measurements highlight the ability of this technique to process broadband analog optical pseudorandom noise waveforms.