Homogeneously broadened delay-line oscillators such as lasers or optoelectronic oscillators (OEOs) can potentially oscillate in a large number of cavity modes that are supported by their amplifier bandwidth. In a continuous wave operating mode, the oscillating mode is selected between one or few cavity modes that experience the highest small-signal gain. In this manuscript, we show that the oscillation mode of a homogeneously broadened oscillator can be selected from a large number of modes in a frequency region that can be broader than the full width at half maximum of the effective cavity filter. The mode is selected by a short-time injection of an external signal into the oscillator. After the external signal is turned off, the oscillation is maintained in the selected mode even if this mode has a significantly lower small-signal gain than that of other cavity modes. The stability of the oscillation is obtained due to nonlinear saturation effect in the oscillator amplifier. We demonstrate, experimentally and theoretically, mode selection in a long cavity OEO. We could select any desired mode between 400 cavity modes while maintaining ultra-low phase noise in the selected mode and in the non-oscillating modes. No mode-hopping was observed during our maximum measurement duration of about 24 hours.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1364/OE.25.010632 | DOI Listing |
Sci Adv
January 2025
Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziadzka 5, 87-100 Torun, Poland.
Measuring low light absorption with combined uncertainty <1 per mil (‰) is crucial for many applications. Popular cavity ring-down spectroscopy can provide ultrahigh precision, below 0.01‰, but its accuracy is often worse than 5‰ due to inaccuracies in light intensity measurements.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
University of Michigan, Department of Physics, Ann Arbor, Michigan 48109, USA.
Anisotropy is a fundamental property of both material and photonic systems. The interplay between material and photonic anisotropies, however, has hardly been explored due to the vastly different length scales. Here we demonstrate exciton polaritons in a 2D antiferromagnet, CrSBr, coupled with an anisotropic photonic crystal cavity, where the spin, atomic, and photonic anisotropies are strongly correlated.
View Article and Find Full Text PDFState-of-the-art laser frequency stabilization is limited by miniscule length changes caused by thermal noise. In this work, a cavity-length-insensitive frequency stabilization scheme is implemented using strong dispersion in a 21 mm long cavity with a europium-ion-doped spacer of yttrium orthosilicate. A number of limiting factors for slow light laser stabilization are evaluated, including the inhomogeneous and homogeneous linewidth of the ions, the deterioration of spectral windows, and the linewidth of the cavity modes.
View Article and Find Full Text PDFOptical properties of InGaN/GaN red quantum well(QW) and their microcavities were studied and compared under optical pumping. Incidence of the excitation laser from the p-side was employed for both structures in order to acquire better emission characteristics. The QW structure was grown on sapphire substrate by metalorganic vapor-phase epitaxy(MOVPE) with a blue pre-layer QW.
View Article and Find Full Text PDFThe optical properties of the 1D nanograting chip have been explored based on computational and experimental studies. Dispersion curve analysis demonstrates cavity and surface plasmon modes in the 1D nanograting chips with periods of 400 nm and 800 nm. In this grating period range, the cut-off period is at a grating period of 644 nm under excitation with a wavelength of 670 nm.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!