Abstract Nonlinear Kerr micro-resonators have enabled fundamental breakthroughs in the understanding of dissipative solitons, as well their application to optical frequency comb generation. However, conversion efficiency pump power into a soliton typically remains below few percent. We fabricate and characterize hybrid Mach-Zehnder ring resonator geometry, consisting micro-ring embedded an additional cavity with twice path length ring. The resulting interferometric back coupling enables...

Dispersion engineering in silicon nitride (SiXNY) waveguides is investigated through the optimization of waveguide transversal dimensions and refractive indices a multicladding arrangement. Ultraflat dispersion −84.0±0.5  ps/nm/km between 1700 2440 nm 1.5±3  ps/nm/km 1670 2500 nm numerically demonstrated. It shown that typical index fluctuations as well dimension during fabrication SiXNY are limitation for obtaining ultraflat profiles....

Abstract. Step-by-step, time-consuming scanning of the sample is still state-of-the-art in imaging Raman spectroscopy. Even for a few 100 image points measurement time may add up to minutes or hours. A radical decrease can be achieved by applying multiplex spectrographs coupled fiber bundles that are successfully used astronomy. For optimal use scarce and expensive observation at astronomical observatories, special high-performance spectrograph systems were developed. They designed recording...

Nonlinear frequency conversion spanning from the ultraviolet to mid-infrared (beyond 2.4 μm) is experimentally demonstrated in multicladding silicon nitride (SiXNY) waveguides. By adjusting waveguide cross-section chromatic dispersion flattened, which enhances both efficiency and bandwidth of nonlinear conversion. How accurately tailored assessed through measurements an experiment/simulation comparison dispersive waves' wavelength locations. Undesirable fluctuations refractive index...

Photonic Integrated Circuits (PIC) are best known for their important role in the telecommunication sector, e.g. high speed communication devices data centers. However, PIC also hold promise innovation sectors like life science, medicine, sensing, automotive etc. The past two decades have seen efforts of utilizing to enhance performance instrumentation astronomical telescopes, perhaps most spectacular example being integrated optics beam combiner interferometer GRAVITY at ESO Very Large...

We here discuss recent progress on astronomical optical frequency comb generation at innoFSPEC-Potsdam. Two different platforms (and approaches) are numerically and experimentally investigated targeting medium low resolution spectrographs facilities in which innoFSPEC is currently involved. In the first approach, a generated by propagating two lasers through three nonlinear stages – serve for of low-noise ultra-short pulses, while final stage low-dispersion highly-nonlinear fibre where...

The generation of a broadband optical frequency comb with 80 GHz spacing by propagation sinusoidal wave through three dispersion-optimized nonlinear stages is numerically investigated. input power, the dispersion, coefficient, and lengths are optimized for first two low-noise ultra-short pulses. final stage low-dispersion highly-nonlinear fibre where pulses undergo self-phase modulation strong spectral broadening. modeling performed using Generalized Nonlinear Schrodinger Equation...

Abstract Astrophysicists use Integral Field Spectroscopy to record spectrally resolved images of faint galaxies. Transferred imaging Raman spectroscopy, this technique significantly accelerates the capture as simultaneous acquisition multiple spectra makes scanning procedures obsolete. Furthermore, sequentially collected result in image sequences thus allowing monitor features spatial dimension over time. However, long readout times required large‐area charge coupled device detectors slow...

We here report on recent progress astronomical optical frequency comb generation at innoFSPEC-Potsdam and present preliminary test results using the fiber-fed Multi Unit Spectroscopic Explorer (MUSE) spectrograph. The is generated by propagating two free-running lasers 1554.3 1558.9 nm through dispersionoptimized nonlinear fibers. centered 1590 comprises more than one hundred lines with an optical-signal-to-noise ratio larger 30 dB. A crystal used to double whole spectrum, which efficiently...

A technique for flattening the chromatic dispersion in silicon nitride waveguides with silica cladding is proposed and numerically investigated. By modifying transversal dimensions of core by adding several layers appropriate refractive indices thicknesses, we demonstrate over large spectral bandwidths near infrared. We analyze index profiles that could be realistically fabricated using existing materials doping procedures. show engineering allows much more control (and flattening)...

We investigate frequency comb generation in silicon nitride ring resonators by using a pump subject to weak amplitude modulation. show that partial locking is obtained when the external modulation differs from resonator free-spectral-range up hundreds of MHz.

Dispersion-flattening in silicon-nitride waveguides (dispersion variation of ±3ps/nm/km over 400nm) is demonstrated by optimizing the refractive indices and thicknesses three cladding layers. SC generation spanning octaves shown those waveguides.

As part of ongoing efforts towards development integrated optoelectronic platforms on a single chip, specifically photonic spectrographs for Astronomy, we report numerical and experimental results from dispersion engineering in silicon nitride waveguides.

The accurate characterization of the field at output optical fibres is relevance for precision spectroscopy in astronomy. modal effects fibre translate to illumination pupil spectrograph and impact on resulting point spread function (PSF). A Model presented that based Eigenmode Expansion Method (EEM) calculates from a given different manipulations input field. design modes calculation are done via commercially available Rsoft-FemSIM software. We developed Python script apply EEM. Results...

The engineering of the propagation constant in integrated silicon nitride waveguides is numerically investigated. We compare several geometrical designs and show that fairly large chromatic dispersion control obtained when transversal dimensions are modified.

Silicon nitride ring resonators with diameter of 250 and 500 μm are fabricated their spectral characteristics investigated the ultimate goal optical frequency comb generation for astronomical spectrograph calibration. A continuously tunable laser was used to evaluate (propagation losses transmission properties) PECVD silicon waveguides ring-resonators. Losses were measured be smaller than 0.75 dB/cm over range between 1500 nm 1620 nm. The properties assessed TE TM modes, showing promise...

The ability to arbitrarily control the chromatic dispersion in CMOS-compatible waveguides should strengthen viability of this technology, particularly for nonlinear devices on a chip [1]. Here we report systematic investigation group velocity engineering channel and rib with silicon nitride core (Si <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> N xmlns:xlink="http://www.w3.org/1999/xlink">4</inf> ). is done by including three cladding...

Abstract For near‐infrared ground and space‐based astronomy, compact photonic devices can replace the large bulk optical components in spectrographs, frequency combs, beam combiners, sky subtraction filters, thus saving cost, reducing volume, weight, power requirements. Photonic integrated circuits (PICs), analogous to (IC) electronics, are particularly powerful address innovative miniaturized solutions. Here, we demonstrate two new instrument prototypes: Potsdam Arrayed Waveguide...

We investigate theoretically and experimentally the mode interaction in an integrated Silicon Nitride (Si3N4) microring resonator with interferometric coupling realized by a feedback loop as adjustable optical path length connecting ring to bus waveguide at two sections. From transmission spectra recorded different lengths, resonances, 1596.5~nm 1570.5~nm, were selected for detailed investigation. Both resonances show possibility of adjusting resonance width depth. However, around first also...

Frequency combs in a Silicon-Nitride-Microring resonator with an ultra-stable repetition frequency of 28.55 GHz were generated by means amplitude modulated pump laser at 1568.8 nm and compared to numerical calculation based on modified Lugiato-Lefever-Equation. The comb spectrum power level -40 dB respect the line spans wavelength range 70 nm.

The generation of dissipative Kerr solitons is experimentally investigated in ring resonators with optical feedback. This new double-resonator geometry allows generating frequency combs smooth solitonic spectral shape over much broader bandwidths if compared the standard resonator architecture. By using an amplitude modulated pump, repetition rate generated comb locked to external modulation and exhibits a stability comparable modulating radio signal, i.e. linewidth very narrow (20 Hz)....