Deeply Etched Inner-Cavity Pit Reflector

P‐substrate InP‐based 1.5 μm lasers using an internal carbon‐doped layer to block p‐dopant diffusion

“…The threshold currents of the two lasers are equivalent to n-substrate counterparts of equivalent length and ridge width. 9,10 Pulse testing of the first growth allowed the material to lase at high currents, with the spectrum centered at 1.5 μm, Figure 5, indicating that the QWs had been correctly designed but that the optical efficiency had been greatly reduced. A Fourier transform of the optical spectra was used to extract the cleaved cavity length 11 and indicates that the cleaved facets were unharmed and not responsible for the failure to lase.…”

“…8,9 While Eplane septa is a crucial item in filter design, it has only been applied to wide bandwidth BPF. 10 Moreover, considering the complexity of forming passbands directly, it is more convenient to allocate transmission zeros suitably to the whole band for more passbands. In this letter, multiband BPF design for waveguide application is proposed, which utilizes E-plane septa to introduce transmission zeros in-band for flexible realization of multiband.…”

Regrowth-free single-mode semiconductor laser suitable for monolithic integration based on pits mirror

“…31,32 More details about the pit characteristics and features and comparison with a slot can be found in previous work. 24 Finally, the last part of the laser consists of a waveguide section with an angled cleaved facet (blue). As shown in Fig.…”

“…Mode selectivity is attained using a compact mirror with a length of 170 μm consisting of 1 μm × 1 μm deeply etched and closely spaced pits. 24 A small pit spacing was used to ensure a large (60 nm) free spectral range, which ensured that the laser operated in a narrow wavelength region (1 nm) over a large range of temperature and bias current. The laser achieves a single mode with an SMSR of 37 dB, a linewidth of 450 kHz and is thermally tunable across 2.9 nm.…”

Single facet semiconductor laser with deep etched V-notch reflectors integrated with an active multimode interference reflector

“…In order to provide a better depth consistency, a combination of dry etch and wet chemical etch steps can be used (9). However, using the wet chemical etch will increase the fabrication complexity due to the influence of crystal orientation on chemical etching of InP (10)(11)(12).…”