Characterization of Hybrid InP-TriPleX Photonic Integrated Tunable Lasers Based on Silicon Nitride (Si ₃N₄/SiO₂) Microring Resonators for Optical Coherent System

Abstract

We demonstrate detailed characterization results of a hybrid InP-TriPleX photonic integrated tunable laser based on silicon nitride microring resonators. A tuning range of 50 nm across the C-band, side-mode suppression ratio (SMSR) >50 dB, high output power (∼10 dBm), linewidth of <80 kHz across the whole tuning range, and µs switching speed are achieved. The delayed self-heterodyne (DSH) method is used for the linewidth measurement, the lowest linewidth can be achieve is ∼35 kHz. The FM noise spectrum is also measured to show the 1/f noise and white noise characterization. Furthermore, the device demonstrates performance comparable with commercial external cavity lasers in 64-QAM coherent system.

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

“…Multiplying the single-sided PSD noise level of 700 ± 230 Hz 2 /Hz with π results in an intrinsic linewidth of 2.2 ± 0.7 kHz. This value is 4.5 times smaller than the previously reported value of 10 kHz for a similar InP-Si3N4 hybrid laser based on Vernier filters comprising two microring resonators [26]. We attribute this improvement mainly to a 4.6 times higher factor of pump current above threshold current in our measurement.…”

“…For an experimental demonstration, we use a hybrid integrated InP diode laser as shown in Fig. 2 (a), with a waveguide circuit design similar to [21,22,23,24,25,26,27]. For single-frequency operation, wide wavelength tuning, and for narrow linewidth oscillation through cavity length extension, we use a low-loss Si3N4 waveguide circuit, which provides frequency-selective feedback.…”

“…1 (a). Filters that enhance the photon cavity lifetime are typically resonator based [20,21,22,23,24,25,26,27,28,29] and rely on the light circulating multiple times within the resonator per roundtrip through the laser cavity. The multiple passes through the resonator effectively extend the cavity length, Lc3 to beyond the physical mirror Figure 2: (a) Schematic view of the integrated laser.…”

Hybrid Integrated Semiconductor Lasers with Silicon Nitride Feedback Circuits

“…With the automatic phase tuning turned on, the laser output is seen to increase approximately continuously with pump current (red crosses). With the investigated laser we measure a maximum fiber-coupled optical power of 24 mW, which is more than the previous reported values of 1.7 mW [140], 7.4 mW [82], and 10 mW [144] obtained with similar lasers. When increasing the output coupling from zero to 100%, the threshold current increases from 8 to 19 mA, and the slope efficiency increases from zero to 0.13 mW/mA.…”

Integrated Thermal Silica Micro-Resonator Waveguide System With Ultra-Low Fluorescence

“…They combine high Q-factor, high energy density, and small footprint within a single device and hence allow for the miniaturization of optical setups in various fields of application, e.g. for the reduction of diode laser frequency noise with resonant optical feedback [1], as well as the realization of high efficient non-linear optics such as second harmonic generation [2]. Completely new applications such as the realization of Kerr combs have been demonstrated [3].…”