arXiv subjects

Edwin J. Klein

Publications and source records attributed to Edwin J. Klein.

3 recordsLinked to original sources

arXiv2019

Ring resonator enhanced mode-hop-free wavelength tuning of an integrated extended-cavity laser

Extending the cavity length of diode lasers with feedback from Bragg structures and ring resonators is highly effective for obtaining ultra-narrow laser linewidths. However, cavity length extension also decreases the free-spectral range of the cavity. This reduces the wavelength range of continuous laser tuning that can be achieved with a given phase shift of an intracavity phase tuning element. We present a method that increases the range of continuous tuning to that of a short equivalent laser cavity, while maintaining the ultra-narrow linewidth of a long cavity. Using a single-frequency hybrid integrated InP-Si3N4 diode laser with 120 nm coverage around 1540 nm, with a maximum output of 24 mW and lowest intrinsic linewidth of 2.2 kHz, we demonstrate a six-fold increased continuous and mode-hop-free tuning range of 0.22 nm (28 GHz) as compared to the free-spectral range of the laser cavity.

physics.optics↗

arXiv2019

Hybrid integrated semiconductor lasers with silicon nitride feedback circuits

Hybrid integrated semiconductor laser sources offering extremely narrow spectral linewidth as well as compatibility for embedding into integrated photonic circuits are of high importance for a wide range of applications. We present an overview on our recently developed hybrid-integrated diode lasers with feedback from low-loss silicon nitride (Si3N4 in SiO2) circuits, to provide sub-100-Hz-level intrinsic linewidths, up to 120 nm spectral coverage around 1.55 um wavelength, and an output power above 100 mW. We show dual-wavelength operation, dual-gain operation, laser frequency comb generation, and present work towards realizing a visible-light hybrid integrated diode laser.

physics.optics↗

arXiv2019

Integrated frequency comb laser with narrow intrinsic optical linewidth based on a dielectric waveguide feedback circuit

We present an integrated hybrid semiconductor-dielectric (InP-Si$_3$N$_4$) waveguide laser that generates frequency combs at a wavelength around 1.5 $μ$m with a record-low intrinsic optical linewidth of 34 kHz. This is achieved by extending the cavity photon lifetime using a low-loss dielectric waveguide circuit. In our experimental demonstration, the on-chip, effective optical path length of the laser cavity is extended to 6 cm. The resulting linewidth narrowing shows the high potential of on-chip, highly coherent frequency combs with direct electrical pumping, based on hybrid and heterogeneous integrated circuits making use of low-loss dielectric waveguides.

physics.optics↗