Microwave Photonic Bandpass Filter Based on Carrier-Suppressed Single Sideband Injected Distributed Feedback Laser

Laser diodes with modulated optical injection: towards a simple signal processing unit?

“…Of course, for systems targeting the generation of specific signals, the input is well controlled and there is thus no need to investigate the impact of an arbitrary input. On the other hand, when considering filtering applications-as in [21][22][23][24]-the fact that the laser diode is a dynamically active device becomes a key issue. In this context, the work described in [22][23][24] is particularly interesting: the authors propose schemes based on injection-locked lasers to filter an input signal.…”

“…On the other hand, when considering filtering applications-as in [21][22][23][24]-the fact that the laser diode is a dynamically active device becomes a key issue. In this context, the work described in [22][23][24] is particularly interesting: the authors propose schemes based on injection-locked lasers to filter an input signal. Initially, such schemes relied on Fabry-Perot resonators, which were then upgraded with a semiconductor optical amplifier inside the cavity to improve its selectivity through the increase of the cavity Q-factor [25,26].…”

“…From then on, the system becomes active, and the wavelength selection occurs via the injection locking mechanism: if the input wavelength is close enough to that of the laser, then the laser is locked onto this wavelength, while other wavelengths will simply not be picked up. This works for potentially all longitudinal modes of the Fabry-Perot laser [5], but the use of single-mode distributed Bragg reflectors or distributed feedback lasers has been proposed to limit this periodicity [22][23][24]. Although using a laser in place of an amplified resonant cavity seems to be a convincing progress, one should also take into account that optical injection is known for triggering a wide variety of complex dynamical behaviour, including oscillations, excitability and chaos when the laser is not locked [27].…”

Bias-Free Silicon-Based Optical Single-Sideband Modulator Without 2nd-Order Sideband

“…Optical single-sideband (OSSB) modulation is vital for many MWP applications such as radio over fiber transmission [16], MWP phase shifters [17], [18], MWP mixers [19], [20], MWP filters [21], MWP vector network analyzers [22], MWP feed network for array antennas [23], etc. Several approaches have already been proposed to implement OSSB electro-optic modulators such as using a dual-drive MZM (DDMZM) with RF hybrid couplers [24], based on Sagnac loop [25], [26], using an optical filter to eliminate one of the optical sidebands [27], based on polarization modulator (PolM) [18], [28].…”

“…Carrier suppression has many applications e.g. in filter design [21]. Equal carrier to sideband (i.e.…”