Spectral hole burning for wideband, high-resolution radio-frequency spectrum analysis

Abstract

We present experimental results for what is to our knowledge the first spectral-hole-burning based rf spectrum analyzer to cover 10 GHz of rf analysis bandwidth. The rf signal of interest is modulated onto an optical carrier, and the resultant optical sidebands are burned into the inhomogeneously broadened absorption band of a Tm3+:YAG crystal. At the same time a second, frequency-swept laser reads out the absorption profile, which is a double-sideband replica of the rf spectrum, and thus the rf spectrum can be deduced after spectral calibration of the nonlinear readout chirp. This initial demonstration shows spectral analysis covering 10 GHz of bandwidth with >5500 spectral channels and provides 43 dB of dynamic range.

Photon echo chirp transform using a stabilized frequency agile laser

“…As compared to the so-called photographic architecture of Refs. [8,9] an important difference is the bandwidth of the output signal. Whereas the photographic architecture outputs a low bandwidth signal from a high bandwidth input signal the chirp transform approach outputs a signal with the same bandwidth as the input one.…”

“…The scientific community promoting PE processing is developing dedicated devices and systems such as Doppler correlators [4], true-time delay lines [5], and RF signals spectral analyzers [6][7][8][9]. Nowadays, the more advanced PE demonstrators have surpassed conventional technologies (electronics, acousto-optics) in terms of analog bandwidth [4,6,8,9].…”

“…Nowadays, the more advanced PE demonstrators have surpassed conventional technologies (electronics, acousto-optics) in terms of analog bandwidth [4,6,8,9]. The only limitation toward the extension to full crystal bandwidth and resolution stems from frequency agile laser technology.…”

Wideband RF spectral analyzer based on spectral-spatial holography in : achieved with a highly stabilized frequency chirped laser

“…However, it suffers from two main drawbacks: (i) its spatial demultiplexing principle makes the channel capacity difficult to increase; (ii) its optical scheme is rather complicated to implement. Recently a more direct and completely different approach called ''photographic scheme'' based on Tm 3þ :YAG crystal SHB spectrum analyzer has been developed [4,5]. It consists in engraving the optically carried RF signals to be analyzed in the populations of the rare-earth-ions by SHB phenomenon and to read the spectra with a chirped laser.…”

“…It consists in engraving the optically carried RF signals to be analyzed in the populations of the rare-earth-ions by SHB phenomenon and to read the spectra with a chirped laser. Both systems have demonstrated a 10-GHz bandwidth with 10 000 channels capacity and a resolution in the MHz range [4,5]. The weakness of the ''photographic scheme'' spectral analyzer is its dynamic range of 20 dB which is limited by the presence of a large background signal.…”