Low-Cost Optoelectronic Self-Injection-Locked Oscillators

Abstract

Abstract-We demonstrate a new configuration for an optoelectronic self-injection-locked (SIL) oscillator, where a part of the electrical output signal is self-injected after passing through a long optical delay line for output phase-noise reduction. The SIL oscillator consists of an electrical free-running oscillator and a long optical feedback loop. For the compact and low cost configuration, the free-running oscillator is realized with an InP HPT-based monolithic oscillator and electrical-to-optical conversion is carried out by two low-speed and low-cost laser diodes. With this new configuration, we achieve more than 55-dB phase-noise reduction at 10-kHz frequency offset from the center frequency of about 10.8 GHz by injecting 8-dBm optical signals without using any high-speed optoelectronic components.Index Terms-InP monolithic oscillator, optoelectronic oscillator (OEO), phase-noise reduction, self-injection locking (SIL).

Resonant Tunnelling Optoelectronic Circuits

“…Since RF resonator-based oscillator technology can not match all advantages of photonic systems, there has been a great search of OEO configurations capable to generate ultra-pure RF carriers in both electrical and optical domains. Several OEO systems have been proposed over the last few years, including photonic oscillators based on InP monolithic oscillators [8], or using direct modulated semiconductor lasers and optical/optoelectronic injection schemes [9]. However, these configurations either are too complex or do not meet all the photonic RF systems OEO requirements.…”

“…This five port RTD based OEO circuit eliminates the need of discrete components such as RF amplifiers, RF couplers and filters, and corresponds to a significant simplification when compared to previously reported optoelectronic oscillators [8,9,12]. The RTD-OEO circuit proposed here aims to fulfill the needs of photonic RF systems and is much simpler and flexible due to RTD-OW optoelectronic nonlinearities and the RTD wide bandwidth negative differential conductance (NDC) characteristic.…”

Optoelectronic Oscillators for Communication Systems

“…For detailed information on the RTD and LD, see [3] and [7]. This five port RTD based OEO circuit eliminates the need of discrete components such as RF amplifiers, RF couplers and filters, and corresponds to a significant simplification when compared to previously reported optoelectronic oscillators [8,9,12]. The RTD-OEO circuit proposed here aims to fulfill the needs of photonic RF systems and is much simpler and flexible due to RTD-OW optoelectronic nonlinearities and the RTD wide bandwidth negative differential conductance (NDC) characteristic.…”

Self-injection locked phase-locked loop OEO

“…The opto-electronic oscillator (OEO) [1,[8][9][10][11][12][13][14] can achieve better phase noise performance at 10 GHz and above as compared to the traditional frequency multiplier and synthesis approaches. For example, 10 GHz OEO is commercially available [15] with phase noise levels of -140dBc/Hz at 10 kHz offset carrier.…”

“…These high Q operation OEO with their low phase noise performance could be employed as a highly stable sources to force-oscillate a small size low stability RF oscillator; the standard forced oscillation techniques of injection locking (IL) and phase-locked loop (PLL) are two viable methods for further phase noise reduction by introducing external frequency reference to the oscillator [16][17][18], where the lowest achievable phase noise of these techniques is limited by the phase noise of the external reference source. The concepts of external forced oscillations could not be extended to the already record setting OEO to further stabilize them, but nonetheless, as demonstrated in [9][10][11][12][13][14] self-forced oscillation could be provided as a method to further reduce close-in to carrier phase noise of oscillators.…”