Low-Noise X-Band Tunable Microwave Generator Based on a Semiconductor Laser With Feedback

Abstract

The stabilization of a relatively simple microwave oscillator tunable across the full X-band based on a laser subjected to optical feedback is achieved. Specifically, a resonance effect based on locking the two inherent dynamic frequencies of the system, as well as optoelectronic feedback are utilized to achieve a sub-ps jitter and typical phase noise in the range of −107 dBc/Hz at 10 kHz offset from an oscillation frequency that can be tuned from 5.5 to 12.1 GHz. Further, the microwave signal is extracted from the laser-diode injection terminals and eliminates the need for multiple lasers, radio-frequency filters, and external RF sources. This architecture therefore realizes a compact and low-cost microwave photonic oscillator.

Resonances between fundamental frequencies for lasers with large delayed feedbacks

“…Resonant effects between fundamental frequencies in a delayed feedback laser system may sufficiently stabilize the laser output as has been recently demonstrated in Ref. [11]. The simplest laser system operating with a delayed feedback is the laser subject to an optoelectronic feedback on the injection current.…”

Staircase Dynamics of a Photonic Microwave Oscillator Based on a Laser Diode with Delayed Optoelectronic Feedback

“…1 (see Ref. [9] for device and equipment details). The feedback loop is composed of optical free space (red), optical fiber (blue), and electronic (black) parts with total delay (τ ) of 9.85 ns.…”

“…Semiconductor laser diodes (LDs) subjected to optoelectronic (OE) feedback on their injection current J have been a testbed for studying nonlinear dynamics in timedelayed systems for decades [1][2][3][4]. On the one hand, they provide an opportunity to study rich dynamical behaviors [5][6][7]; on the other, optoelectronic feedback systems have diverse applications ranging from microwave photonic generation [8,9] to controlled wideband frequency chirps [10] as well as in communications [11]. Optoelectronic oscillators with time delayed feedback and their applications are reviewed in Ref.…”

“…Subsequent works consider the distinction between negative [6,15,16] and positive [5,17] OE feedback. In the case of negative feedback, the fed-back current is subtracted from J and is reported to be useful for tunable microwave [9] and optical short-pulse generation [18] by stabilizing the dynamical states. In this instance, the dynamics resulting from a locking between the RO frequency f RO and the feedback-loop frequency f τ (inverse of the delay time τ ), and rational fractions of f RO and f τ participate in various dynamical states [6,19].…”

“…[25], also with optical feedback, switching between LCs (also separated by f τ ) is experimentally observed around the same ECM as well as two different ECMs as η is varied, which is closer to the scenario reported here. To our knowledge none of the reports on OE feedback [5][6][7]9] have presented the analysis of switching between periodic states with distinct microwave frequencies.…”