We demonstrate a hybrid photonic integrated laser that exhibits an intrinsic linewidth of 40 Hz, while offering unsurpassed megahertz actuation bandwidth with the tuning range larger than 1 GHz, attained by a DFB laser self-injection locking to a high-Q Si3N4 microresonator with AlN piezoelectrical actuator, allowing both single-line operation and microcomb generation. We develop a compact FMCW LiDAR engine with triangular chirp optical signals at a rate up to 1 MHz, without requiring any linearisation.
Recent works on Kerr frequency combs demonstrated the possibility to simultaneously generate multiple soliton states with different group velocities in a single microresonator, which could be beneficial for many applications utilizing dual-comb systems. In this work we demonstrate a dual-comb configuration in a single crystalline microresonator by monochromatically pumping counter-propagating solitons in the same spatial mode with equal powers. Moreover, we demonstrate experimentally and through simulations the key role of Cherenkov radiation interferences on the repetition rate of a multi-soliton state. This result not only shines new light on the impact of dispersive waves on dissipative Kerr solitons but also introduces a novel approach to develop coherent dual-comb spectrometer based on microcombs.
Kerr-lens mode locked lasers based on polycrystalline Cr:ZnS and Cr:ZnSe have come of age and, arguably, represent the most viable route for generation of ultra-short pulses in the range 2–3 μm. Developed designs of Kerr-lens mode locked oscillators feature high efficiency and provide access to few-cycle MIR pulses with Watt-level power in a very broad range of pulse repetition rates. However, currently available dispersive mirror coatings limit spectral coverage of these oscillators to below one octave hampering their conversion to frequency combs via frequency envelop offset frequency (fceo) control and stabilization. Supercontinuum (SC) generation using photonic waveguides is a promising approach for spectral broadening of pulsed coherent sources at low pulse energies and small footprint. Among many materials promising for this application stoichiomentric Si3N4 (SiN) holds a unique place due to its high nonlinearity, CMOS compatible fabrication process, and spectral coverage over visible-middle-infrared (MIR) range. In the current paper we experimentally demonstrate the generation of a supercontinuum spanning more than 1.5 octaves over 1.2-3.7 um range in a silicon nitride waveguide using sub-40-fs pulses at 2.35 um generated by 75 MHz Cr:ZnS laser. The coupling efficiency was about 16%, which corresponds to 0.56nJ pulse energy and 12.4 kW peak power. We also have observed that threshold for SC generation was about 50 mW of incident power that corresponds to 2.4KW peak power. The demonstrated coherent 1.5 octaves spanning bandwidth is ideal for self-referenced f-2f detection of the fceo. In addition, this represents a promising broadband coherent source for dual comb spectroscopy.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.