A linearized analog photonic link (APL) is proposed based on an integratable electro-optic dual-parallel polarization modulator (DPPolM), which consists of two polarization beam splitters and two polarization modulators (PolMs). Theoretical analysis shows that the APL is potentially free from the third-order nonlinear distortion if a polarization controller placed before the DPPolM is carefully adjusted. A proof-of-concept experiment is carried out. A reduction of the third-order intermodulation components as high as 40 dB and an improvement of the spurious-free dynamic range as large as 15.5 dB is achieved as compared with a single PolM-based link. The DPPolM-based APL is simple, compact, and power efficient since it requires only one laser, one modulator, and one photodetector.

A photonic approach to the simultaneous measurement of the frequency, pulse amplitude (PA), pulse width (PW), and time of arrival (TOA) of an unknown pulsed microwave signal is proposed and demonstrated. The measurement is performed based on optical carrier-suppressed modulation, complementary optical filtering, low-speed photodetection, and electrical signal processing. A proof-of-concept experiment is carried out. A frequency measurement range of 2-11 GHz with a measurement error for frequency, PA, PW, and TOA within ±0.1 GHz, ±0.05 V, ±1 ns, and ±0.16 ns is achieved.

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A fiber-connected ultra-wideband (UWB) sensor network for high-resolution localization which consists of a central station and several sensor nodes is proposed and demonstrated. To make the central station easily identify the received UWB pulses from different sensor nodes, optical time-division multiplexing (OTDM), realized by inserting a certain length of optical fiber between every two sensor nodes, is implemented. Due to the OTDM technology, the UWB pulses received by different sensors are mapped into different time slots, so neither parameter estimation nor clock synchronization is required in the UWB sensor node. All complex signal processing is completed in the central station, which greatly improve the localization accuracy and simplify the system. A proof-of-concept experiment for two-dimensional localization is demonstrated. Spatial resolution as high as 3.9 cm is achieved.

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An ultrahigh-resolution and wideband optical vector analyzer (OVA) with the simplest architecture, to the best of our knowledge, is proposed and demonstrated based on chirped optical double-sideband (ODSB) modulation in a single-drive Mach-Zehnder modulator (MZM). To distinguish the magnitude and phase information carried by the two sidebands in the ODSB signal, a two-step measurement, in which biasing, respectively, the MZM at two different points is applied. Because no optical filtering is required in the scheme, the optical carrier can be located at any wavelength that is suitable for accurate measurement, e.g., close to the notch of a notch response or within the passband of a bandpass response, so the proposed OVA has the capability to measure an arbitrary response. An experiment is carried out, which achieves the magnitude and phase responses of a programmable optical processor with bandpass, notch, or falling-edge responses. The measurement bandwidth is 134 GHz, and the measurement resolution is 1.12 MHz.

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A fiber-distributed Ultra-wideband (UWB) noise radar was achieved, which consists of a chaotic UWB noise source based on optoelectronic oscillator (OEO), a fiber-distributed transmission link, a colorless base station (BS), and a cross-correlation processing module. Due to a polarization modulation based microwave photonic filter and an electrical UWB pass-band filter embedded in the feedback loop of the OEO, the power spectrum of chaotic UWB signal could be shaped and notch-filtered to avoid the spectrum-overlay-induced interference to the narrow band signals. Meanwhile, the wavelength-reusing could be implemented in the BS by means of the distributed polarization modulation-to-intensity modulation conversion. The experimental comparison for range finding was carried out as the chaotic UWB signal was notch-filtered at 5.2 GHz and 7.8 GHz or not. Measured results indicate that space resolution with cm-level could be realized after 3-km fiber transmission thanks to the excellent self-correlation property of the UWB noise signal provided by the OEO. The performance deterioration of the radar raised by the energy loss of the notch-filtered noise signal was negligible.