Fiber array to chip attach using laser fusion splicing for low loss.

With the ever-increasing need for higher data rates, datacom and telecom industries are now migrating to silicon photonics to achieve higher data rates with reduced manufacturing costs. However, the optical packaging of integrated photonic devices with multiple I/O ports remains a slow and expensive process. We introduce an optical packaging technique to attach fiber arrays to a photonic chip in a single shot using CO2 laser fusion splicing. We show a minimum coupling loss of 1.1 dB, 1.5 dB, and 1.4 dB per-facet for 2, 4, and 8-fiber arrays (respectively) fused to the oxide mode converters using a single shot from the CO2 laser.

Hands-On Photonic Education Kits: empowering the integrated photonics workforce through practical training.

The Hands-On Photonic Education (HOPE) Kits, developed with AIM Photonics, address the need for skilled workers in integrated photonics. This paper highlights the role of the HOPE Kits in advancing the training ecosystem and bridging the skills gap. The kits include fully packaged photonic integrated circuits (PICs), enabling instructors to educate and train students on PIC testing and characterization. Covering a wide range of devices and circuits, from waveguides to wavelength division multiplexing for data communication, the kits offer a hands-on experience. Engaging with actual PICs, students gain practical insights, enhancing their understanding of key principles, and preparing them for real-world skill sets in integrated photonics.

Enhanced on-chip frequency measurement using weak value amplification.

We present an integrated design to sensitively measure changes in optical frequency using weak value amplification with a multi-mode interferometer. The technique involves introducing a weak perturbation to the system and then post-selecting the data in such a way that the signal is amplified without amplifying the technical noise, as has previously been demonstrated in a free-space setup. We demonstrate the advantages of a Bragg grating with two band gaps for obtaining simultaneous, stable high transmission and high dispersion. The device is more robust and easily scalable than the free-space implementation, and provides amplified sensitivity compared to other methods of measuring changes in optical frequency on a chip, such as an integrated Mach-Zehnder interferometer.

Electrically induced adiabatic frequency conversion in an integrated lithium niobate ring resonator.

Changing the frequency of light outside the laser cavity is essential for an integrated photonics platform, especially when the optical frequency of the on-chip light source is fixed or challenging to be tuned precisely. Previous on-chip frequency conversion demonstrations of multiple GHz have limitations of tuning the shifted frequency continuously. To achieve continuous on-chip optical frequency conversion, we electrically tune a lithium niobate ring resonator to induce adiabatic frequency conversion. In this work, frequency shifts of up to 14.3 GHz are achieved by adjusting the voltage of an RF control. With this technique, we can dynamically control light in a cavity within its photon lifetime by tuning the refractive index of the ring resonator electrically.

In Vitro Anthelmintic Evaluation of Gliricidia sepium, Leucaena leucocephala, and Pithecellobium dulce: Fingerprint Analysis of Extracts by UHPLC-Orbitrap Mass Spectrometry.

In the present work, the anthelmintic activity (AA) of ethanolic extracts obtained from Gliricidia sepium, Leucaena leucocephala, and Pithecellobium dulce was evaluated using the third-stage-larval (L3) exsheathment inhibition test (LEIT) and egg hatch test (EHT) on Haemonchus contortus. Extracts were tested at concentrations of 0.3, 0.6, 1.2, 2.5, 5.0, 10, 20, and 40 mg/mL. The larval exsheathment inhibition (LEI) results showed that G. sepium achieved the highest average inhibition of 91.2%, compared with 44.6% for P. dulce and 41.0% for L. leucocephala at a concentration of 40 mg/mL; the corresponding IC50 values were 22.4, 41.7, and 43.3 mg/mL, respectively. The rates of egg hatching inhibition (EHI) at a concentration of 5 mg/mL were 99.5% for G. sepium, 64.2% for P. dulce, and 54% for L. leucocephala; the corresponding IC50 values were 1.9 mg/mL for G. sepium, 3.9 mg/mL for P. dulce, and 4.3 mg/mL for L. leucocephala. The species extracts studied here were also analyzed by ultra-high performance liquid chromatography and Orbitrap high resolution mass spectrometry (UHPLC-Q/Orbitrap/MS/MS), resulting in the compounds' identification associated with AA. Glycosylated flavonoids and methoxyphenols were observed in all three species: fatty acids in G. sepium and P. dulce; phenylpropanoids, anthraquinone glycosides, amino acids and glycosylated phenolic acids in G. sepium; and flavonoids in L. leucocephala. Comparatively, G. sepium presented a greater diversity of compounds potentially active against the control of gastrointestinal nematodes, which was associated with the results obtained in the applied tests.

Carrier envelope offset detection via simultaneous supercontinuum and second-harmonic generation in a silicon nitride waveguide.

We demonstrate a chip-scale f-2f interferometer for carrier-envelope-offset frequency (fCEO) detection. This is enabled by simultaneously producing octave-spanning coherent supercontinuum generation and second-harmonic generation in a single dispersion-engineered silicon nitride waveguide. We measure the fCEO beatnote of an 80 MHz modelocked pump source with a signal-to-noise ratio of 25 dB. Our simple approach for f-2f interferometry enables a straightforward route towards a chip-scale self-referenced frequency comb source that can operate at low pulse energies.

Coherent, directional supercontinuum generation.

We demonstrate a novel approach to producing coherent, directional supercontinuum and cascaded dispersive waves using dispersion engineering in waveguides. By pumping in the normal group-velocity dispersion (GVD) regime, with two zero-GVD points to one side of the pump, pulse compression of the first dispersive wave generated in the anomalous GVD region results in the generation of a second dispersive wave beyond the second zero-GVD point in the normal GVD regime. As a result, we achieve an octave-spanning supercontinuum generated primarily to one side of the pump spectrum. We theoretically investigate the dynamics and show that the generated spectrum is highly coherent. We experimentally confirm this dynamical behavior and the coherence properties in silicon nitride waveguides by performing direct detection of the carrier-envelope-offset frequency of our femtosecond pump source using an f-2f interferometer. Our technique offers a path towards a stabilized, high-power, integrated supercontinuum source with low noise and high coherence, with applications including direct comb spectroscopy.

Coherent mid-infrared frequency combs in silicon-microresonators in the presence of Raman effects.

We demonstrate the first low-noise mid-IR frequency comb source using a silicon microresonator. Our observation of strong Raman scattering lines in the generated comb suggests that interplay between Raman and four-wave mixing plays a role in the generated low-noise state. In addition, we characterize, the intracavity comb generation dynamics using an integrated PIN diode, which takes advantage of the inherent three-photon absorption process in silicon.

Tunable squeezing using coupled ring resonators on a silicon nitride chip.

We demonstrate continuous tuning of the squeezing-level generated in a double-ring optical parametric oscillator by externally controlling the coupling condition using electrically controlled integrated microheaters. We accomplish this by utilizing the avoided crossing exhibited by a pair of coupled silicon nitride microring resonators. We directly detect a change in the squeezing level from 0.5 dB in the undercoupled regime to 2 dB in the overcoupled regime, which corresponds to a change in the generated on-chip squeezing factor from 0.9 to 3.9 dB. Such wide tunability in the squeezing level can be harnessed for on-chip quantum-enhanced sensing protocols that require an optimal degree of squeezing.

Optical nonlinearities in high-confinement silicon carbide waveguides.

We demonstrate strong nonlinearities of n2=8.6±1.1×10(-15) cm2 W(-1) in single-crystal silicon carbide (SiC) at a wavelength of 2360 nm. We use a high-confinement SiC waveguide fabricated based on a high-temperature smart-cut process.

Synchronization and Phase Noise Reduction in Micromechanical Oscillator Arrays Coupled through Light.

Synchronization of many coupled oscillators is widely found in nature and has the potential to revolutionize timing technologies. Here, we demonstrate synchronization in arrays of silicon nitride micromechanical oscillators coupled in an all-to-all configuration purely through an optical radiation field. We show that the phase noise of the synchronized oscillators can be improved by almost 10 dB below the phase noise limit for each individual oscillator. These results open a practical route towards synchronized oscillator networks.

On-chip frequency comb generation at visible wavelengths via simultaneous second- and third-order optical nonlinearities.

Microresonator-based frequency comb generation at or near visible wavelengths would enable applications in precise optical clocks, frequency metrology, and biomedical imaging. Comb generation in the visible has been limited by strong material dispersion and loss at short wavelengths, and only very narrowband comb generation has reached below 800 nm. We use the second-order optical nonlinearity in an integrated high-Q silicon nitride ring resonator cavity to convert a near-infrared frequency comb into the visible range. We simultaneously demonstrate parametric frequency comb generation in the near-infrared, second-harmonic generation, and sum-frequency generation. We measure 17 comb lines converted to visible wavelengths extending to 765 nm.

Athermal silicon microring resonators with titanium oxide cladding.

We describe a novel approach for CMOS-compatible passively temperature insensitive silicon based optical devices using titanium oxide cladding which has a negative thermo-optic (TO) effect. We engineer the mode confinement in Si and TiO2 such that positive TO of Si is exactly cancelled out by negative TO of TiO2. We demonstrate robust operation of the resulting device over 35 degrees.

Linearized silicon modulator based on a ring assisted Mach Zehnder inteferometer.

We demonstrate a Linearized Ring Assisted Mach-Zehnder Interferometer (L-RAMZI) modulator in a miniature silicon device. We measure a record high degree of linearization for a silicon device, with a Spurious Free Dynamic Range (SFDR) of 106dB/Hz²/³ at 1GHz, and 99dB/Hz²/³ at 10GHz.

High Q SiC microresonators.

We demonstrate photonic devices based on standard 3C SiC epitaxially grown on silicon. We achieve high optical confinement by taking advantage of the high stiffness of SiC and undercutting the underlying silicon substrate. We demonstrate a 20 µm radius suspended microring resonator with Q=14,100 fabricated on commercially available SiC-on-silicon substrates.

Morphological characterization of Pelibuey sheep in Colima, México.

A study was conducted with the objective to characterize the morphology of Pelibuey sheep in the state of Colima, Mexico. A total of 386 sheep were scored for 12 body measurements in addition to live weight and five racial and eight functional indices were calculated. The influence of sex on the body measurements and indices was analyzed, and morphological harmony was determined through Pearson correlation. The sexual dimorphism was 1.21, with males being 67 % heavier than females. Females and males had a high and moderate degree of harmony in their morphological model, respectively. Pelibuey sheep were dolichocephalous, tended to be medium- to large-sized according to the thoracic index, with a convex curve rump; they were a homogeneous breed, well adapted to environmental and production conditions of the state of Colima, Mexico, and show an undefined zootechnical aptitude and therefore a great potential to be oriented towards meat or milk production through genetic selection or terminal crossbreeding systems using specialized breeds.

The Advance of Fusarium Wilt Tropical Race 4 in Musaceae of Latin America and the Caribbean: Current Situation.

The fungus Fusarium oxysporum f. sp. cubense tropical race 4 (syn. Fusarium odoratissimum) (Foc TR4) causes vascular wilt in Musaceae plants and is considered the most lethal for these crops. In Latin America and the Caribbean (LAC), it was reported for the first time in Colombia (2019), later in Peru (2021), and recently declared in Venezuela (2023). This work aimed to analyze the evolution of Foc TR4 in Musaceae in LAC between 2018 and 2022. This perspective contains a selection of topics related to Foc TR4 in LAC that address and describe (i) the threat of Foc TR4 in LAC, (ii) a bibliometric analysis of the scientific production of Foc TR4 in LAC, (iii) the current situation of Foc TR4 in Colombia, Peru, and Venezuela, (iv) medium-term prospects in LAC member countries, and (v) export trade and local food security. In this study, the presence of Foc TR4 in Venezuela and the possible consequences of the production of Musaceae in the long term were reported for the first time. In conclusion, TR4 is a major threat to banana production in Latin America and the world, and it is important to take measures to control the spread of the fungus and minimize its impact on the banana industry. It is important to keep working on the control of Foc TR4, which requires the participation of the local and international industry, researchers, and consumers, among others, to prevent the disappearance of bananas.

Nematode predatory ability of the fungus Duddingtonia flagrans affected by in vitro sequential exposure to ovine gastrointestinal tract.

Duddingtonia flagrans is a nematophagous fungus employed as a biocontrol agent of gastrointestinal nematodes in ruminants. After oral ingestion and passage through the digestive tract of animals, this microorganism captures the nematodes in the feces. The drastic conditions of ruminant digestive tract could affect fungi chlamydospores and therefore biocontrol activity. The aim of this study was to evaluate in vitro the effect of four ruminant digestive segments on the concentration and nematode predatory ability of a Colombian native strain of D. flagrans. The sequential four-step methodology proposed evaluated conditions of the oral cavity, rumen, abomasum, and small intestine such as pH (2, 6, 8), enzymes (pepsin, pancreatin), temperature (39 °C), and anaerobiosis comparing short (7 h) and long (51 h) exposure times. The results showed that the nematode predatory ability of the fungi is affected by sequential exposure to gastrointestinal segments and this effect depends on the exposure time to those conditions. After short exposure (7 h) through the four ruminant digestive segments, the fungi had a nematode predatory ability of 62%, in contrast, after long exposure (51 h) the nematode predatory ability was lost (0%). Moreover, the number of broken chlamydospores was higher in the long-exposure assay.

High quality factor and high confinement silicon resonators using etchless process.

We demonstrate high quality factor and high confinement in a silicon ring resonator fabricated by a thermal oxidation process. We fabricated a 50 µm bending radius racetrack resonator, with a 5 µm coupling region. We achieved an intrinsic quality factor of 760,000 for the fundamental TM mode, which corresponds to a propagation loss of 0.9 dB/cm. Both the fundamental TE and TM modes are highly confined in the waveguide, with effective indices of 3.0 for the TE mode and 2.9 for the TM mode.