Widely Tunable, Low Linewidth, and High Power Laser Source using an Electro-Optic Comb and Injection-Locked Slave Laser Array

We propose a simple approach to implement a tunable, high power and narrow linewidth laser source based on a series of highly coherent tones from an electro-optic frequency comb and a set of 3 DFB slave lasers. We experimentally demonstrate approximately 1.25 THz (10 nm) of tuning within the C-Band centered at 192.9 THz (1555 nm). The output power is approximately 100 mW (20 dBm), with a side band suppression ratio greater than 55 dB, and a linewidth below 400 Hz across the full range of tunability. This approach is scalable and may be extended to cover a significantly broader optical spectral range

Required and received SNRs in coded modulation

Coded modulation techniques aim at reducing the required signal-to-noise ratio (SNR) over the Gaussian channel with an average energy constraint; however, such techniques tend to degrade the received SNR. We studied the balance of required and received SNRs for a realistic system design

Observation of Eisenbud-Wigner-Smith states as principal modes in multimode fibre

Generally, light becomes scattered in space and time as it is coupled among multiple spatial paths during propagation through disordered media or multimode waveguides. This limits the pulse duration and spatial coherence that can be obtained after light exits such a medium. Eisenbud–Wigner–Smith eigenstates, originally proposed in nuclear scattering, are a unique set of input/output states that, despite spatiotemporal scattering during propagation, arrive at the output temporally unscattered. In fibre optics, these states manifest as principal modes that allow pulses and spatial coherence to be maintained despite propagation through a medium that would otherwise have destroyed these properties. These states generalize the phenomena of orthogonal fast/slow axes in a birefringent object to a basis with N axes, where N is the total number of spatial/polarization modes in the scattering medium. We experimentally demonstrate the existence of principal modes using a 100 m length of multimode fibre as the propagation medium

Multimode fibers for telecommunications and imaging

In this paper, we discuss the characterization of light propagation in multimode fiber and its application to telecommunications, imaging and fundamental physics

Characterization of laser inscribed on-chip photonic lanterns with different core distances

We measured the wavelength-dependent transfer matrix of multiple photonic lanterns with different core spacings using a spatially diverse swept-wavelength interferometer. We characterised the mode-coupling and mode-dependent loss for core spacings ranging from 8 to 11 μm

Phase-sensitive amplification in silicon photonic crystal waveguides

We experimentally demonstrate phase-sensitive amplification in a silicon photonic crystal waveguide based on pump-degenerate four-wave mixing. An 11 dB phase-extinction ratio is obtained in a record compact 196 µm nanophotonic device due to broadband slow light, in spite of the presence of two-photon absorption and free carriers. Numerical calculations show good agreement with the experimental results