Paper
14 March 2015 Broadband receiver-based distortion elimination in phase-modulated analog optical links using four-wave mixing
Amit Bhatia, Hong-Fu Ting, Mark A. Foster
Author Affiliations +
Abstract
We present a method for full distortion elimination in phase-modulated analog optical links using the nonlinear optical process of four-wave mixing (FWM). Phase-modulated links consist of a laser and phase modulator in the transmitter and an interferometer (or local oscillator) and photodiode in the receiver. Phase modulation is a linear process, so distortion is introduced in the interferometric detection process. Quadrature biasing eliminates even-order distortion products, leaving only odd-order distortion. Here we introduce a method for eliminating these odd-order distortion products in the receiver. A small portion of the phase-modulated signal is tapped and combined with an unmodulated CW laser to seed a cascaded FWM comb source. This process generates an array of lightwaves with integer multiples of the signal’s phase modulation. By suitably scaling and combining these lightwaves with the original signal the overall transfer function of the interferometric receiver can be linearized (or given another tailored shape) through a Fourier synthesis approach. By combining a single lightwave from the generated comb with the original signal, we demonstrate the complete elimination of third-order distortion from the phase-modulated link leaving fifth-order distortion as the dominate source of distortion. We show a 17.6-dB SFDR improvement (1-Hz bandwidth) for a 6 GHz link operating at 5-mA total photocurrent and a 16.4-dB SFDR improvement (1-Hz bandwidth) for a 15 GHz link operating at 10-mA total photocurrent. By appropriately combining additional lightwaves from the generated comb, higher-order distortion products can be eliminated to produce an ideal linear (or custom shaped) transfer function.
© (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Amit Bhatia, Hong-Fu Ting, and Mark A. Foster "Broadband receiver-based distortion elimination in phase-modulated analog optical links using four-wave mixing", Proc. SPIE 9362, Terahertz, RF, Millimeter, and Submillimeter-Wave Technology and Applications VIII, 936213 (14 March 2015); https://doi.org/10.1117/12.2079807
Lens.org Logo
CITATIONS
Cited by 1 scholarly publication.
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Distortion

Receivers

Interferometry

Analog electronics

Four wave mixing

Modulators

Phase shift keying

Back to Top