Discretely Tunable Laser Based on Filtered Feedback for Telecommunication Applications

Abstract

Abstract-A novel discretely tunable laser based on filtered feedback is presented. The semiconductor device consists of a FabryPerot laser with deeply etched broadband distributed Bragg reflector mirrors. Single-mode operation is achieved by using feedback from an integrated filter. This filter contains an arrayed waveguide grating wavelength router and a semiconductor optical amplifier gate array. Design, simulation, and the first characterization results of this new integrated filtered-feedback tunable laser device are presented. It shows a combination of a simple and robust switching algorithm with good wavelength stability. A rate equation model predicts that a properly designed device can switch within 1 ns. The fast switching and reduced control complexity makes the device very promising for various advanced applications in optical telecommunication networks.

Hybrid Silicon Photonic Integrated Circuit Technology

“…While this device is limited to four channels, it can be easily scaled up to several tens of channels as mature CMOS-manufacturing technology allows the fabrication of high-quality AWGs on SOI. Moreover, fast tuning, increased side-mode suppression, and decreased mode hopping can be achieved by similar designs that are compatible with this study [87], [88].…”

125 Gbit/s discretely tunable InP-on-silicon filtered feedback laser with sub-nanosecond wavelength switching times

“…The reflectivity of DBR HR is larger than 95% whereas DBR Out has a designed reflectivity of 66%, as trade-off between a low threshold current and large output power. The reflectivity of DBR FF controls the filtered feedback strength γ (1/ns), which can phenomenologically be described as [14] …”

“…Assuming the gates are pumped to transparency (A Gate = 1), γ = 11 ns −1 is obtained. With the feedback field being in phase with the propagating field, such filtered feedback strength can enable sub-ns wavelength switching times [14].…”

“…In our implementation the AWG is not part of the main cavity. The filtered feedback concept was first introduced and experimentally demonstrated by B. Docter et al [14], where discrete wavelength tuning was achieved with a pure InP-based laser. The implementation on silicon, however, allows to benefit from the superior passive functionality of silicon, leading to improved static and dynamic lasing characteristics.…”

Compact Photonic Integrated Chip for Tunable Microwave Generation

“…After the intensity profile of the fundamental mode is found, we can determine the effective index of the overall waveguide, which is 3.1896 at λ =1550nm [23], [24]. Other methods, such as 3-dimensional finite-difference timedomain (3D FDTD) simulation, can also perform similar calculations at higher precision but with requirement of greater computer resources [18]. The DBR reflectivity can be then calculated by transmission matrix method [23].…”