Hybrid integrated mode-locked laser diodes with a silicon nitride extended cavity

Integrated semiconductor mode-locked lasers have shown promise in many applications and are readily fabricated using generic InP photonic integration platforms. However, the passive waveguides offered in such platforms have relatively high linear and nonlinear losses that limit the performance of these lasers. By extending such lasers with, for example, an external cavity the performance can be increased considerably. In this paper, we demonstrate for the first time that a high-performance mode-locked laser can be achieved with a butt-coupling integration technique using chip scale silicon nitride waveguides. A platform-independent SiN/SU8 coupler design is used to couple between the silicon nitride external cavity and the III/V active chip. Mode-locked lasers at 2.18 GHz and 15.5 GHz repetition rates are demonstrated with Lorentzian RF linewidths several orders of magnitude smaller than what has been demonstrated on monolithic InP platforms. The RF linewidth was 31 Hz for the 2.18 GHz laser.Comment: Submitted to Optics Expres

Hybrid integrated mode-locked laser using a GaAs-based 1064 nm gain chip and a SiN external cavity

External cavity mode-locked lasers could be used as comb sources for high volume application such as LIDAR and dual comb spectroscopy. Currently demonstrated chip scale integrated mode-locked lasers all operate in the C-band. In this paper, a hybrid-integrated external cavity mode-locked laser working at 1064 nm is demonstrated, a wavelength beneficial for optical coherence tomography or Raman spectroscopy applications. Additionally, optical injection locking is demonstrated, showing an improvement in the optical linewidth, and an increased stability of the comb spectrum

Hybrid integrated mode-locked lasers using silicon nitride external cavities

Optische frequentiekambronnen zijn een veelbelovende lichtbron voor toepassing als spectroscopie, snellere telecommunicatie of LIDAR. Het integreren van deze lichtbronnen op een chip zou het mogelijk maken om de systemen voor deze toepassingen significant te verkleinen, en met behulp van massaproductie ook goedkoper te maken. Dit doctoraat gaat over hybride geïntegreerde modus-vergrendelde lasers, wat een van de methodes is om optische frequentiekammen te genereren met behulp van fotonische chips. Zo'n laser bestaat uit 2 verschillende chips, de caviteitchip en de versterkingschip. Deze worden aan elkaar gekoppeld door de golfgeleiders aan de randen van de chips zeer precies met elkaar te aligneren. Het ontwerp en de fabricage van de caviteitschips is aan de UGent gebeurd, en omschreven in de thesis. De caviteitschips zijn gemaakt van siliciumnitride vanwege de lage optische verliezen in dat platform. Meerdere versterkingschips zijn extern gefabriceerd. Met een combinatie van deze chips zijn twee lasers gemaakt en gekarakteriseerd die werkten zoals verwacht. De eerste was gemaakt met een InP versterkingschip van SMART Photonics. De tweede had een versterkingschip van het Ferdinand-Braun-Institut. Met die laser is ook werkende injectievergrendeling aangetoond

Hybrid integrated mode-locked laser diodes with a silicon nitride extended cavity

Integrated semiconductor mode-locked lasers have shown promise in many applications and are readily fabricated using generic InP photonic integration platforms. However, the passive waveguides offered in such platforms have relatively high linear and nonlinear losses that limit the performance of these lasers. By extending such lasers with, for example, an external cavity, the performance can be increased considerably. In this paper, we demonstrate for the first time that a high-performance mode-locked laser can be achieved with a butt-coupling integration technique using chip scale silicon nitride waveguides. A platform-independent SiN/SU8 coupler design is used to couple between the silicon nitride external cavity and the III/V active chip. Mode-locked lasers at 2.18 GHz and 15.5 GHz repetition rates are demonstrated with Lorentzian RF linewidths several orders of magnitude smaller than what has been demonstrated on monolithic InP platforms. The RF linewidth was 31 Hz for the 2.18 GHz laser. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreemen

Raman Spectroscopy, Free Space and On-Chip

Raman spectroscopy can detect molecules and complex analytes. It can identify molecules based on the vibrational modes. It is very selective technique and label free. It can be used for numerous applications:polymer study, phase identification, study of chemical composition or crystallographic orientation, among others

High-Efficiency Second Harmonic Generation in Heterogeneously-Integrated Periodically-Poled Lithium Niobate on Silicon Nitride

Wavelength conversion processes such as spontaneous parametric down conversion (SPDC) and optical parametric amplification (OPA) are key elements in integrated quantum optics. On-chip integration of these function-alities would allow for increased performance and huge scaling opportunities. However, CMOS-compatible plat-forms such as silicon and silicon nitride (SiN) lack a $chi$(2) nonlinearity due to their inversion symmetry. This work provides a solution by heterogeneously integrating periodically poled lithium niobate (PPLN) onto SiN waveguides through micro-transfer printing (textmuTP) [1]. The textmuTP method is a scalable back-end process, allowing the fabrication of the photonic integrated circuit to remain CMOS-compatible.info:eu-repo/semantics/publishe

Low repetition rate mode-locked laser on a commercial foundry low-index photonic platform

We demonstrate a heterogeneously integrated III-V-on-silicon-nitride mode-locked laser with 710 MHz repetition rate. A versatile two-step micro-transfer printing approach is employed to enable low-loss integration on a commercial foundry low-index photonic platform

High-Speed Photodiodes on Silicon Nitride with a Bandwidth beyond 100 GHz

Next-generation telecommunication systems will rely on photonic integrated circuits. However, Silicon Nitride (SiN) photonic platforms do not natively provide high-speed photodiodes. We integrated a waveguide-coupled UTC photodiode on a SiN platform using the scalable micro-transfer-printing technology. These diodes show a responsivity up to 0.45 A/W, a dark current below 10 nA and a 3 dB-bandwidth beyond 100 GHz, even at zero-bias. As such, high-performance photodetectors are available on silicon-nitride photonic platforms.</jats:p