We analyze the performance of distributed-feedback lasers with special grating structures. These grating structures consist of subgratings with different lengths (that are integer multiples of a reference length) and/or different phase shifts (that are also integer multiples of a reference phase shift). These grating structures can provide transmission peaks with high quality factors, which may be useful for distributed-feedback lasers. To assess the usefulness of these devices, threshold and steady-state analysis are performed for a few selected examples. A given design example is shown to provide a low threshold without major variations in photon density along the device.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1364/ao.46.001283 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
We experimentally demonstrate a cost-effective dual-polarization quadrature phase shift keying (DP-QPSK) coherent passive optical network (PON) system that operates at 100 Gbits/s/λ. This system utilizes distributed feedback lasers (DFBs) and a carrier recovery algorithm facilitated by a bifunctional frequency-domain pilot tone (FPT). To reduce costs in coherent PON implementations, low-cost DFBs are employed as the sole light sources, replacing the more expensive external cavity lasers (ECLs) at both the optical line terminal (OLT) and the optical network units (ONUs).
View Article and Find Full Text PDFCompact and full-range carbon dioxide sensor using photoacoustic and resonance dependent modes.
Photoacoustics
February 2025
Dipartimento di Scienze di Base ed Applicate per l'Ingegneria, Sapienza Università di Roma, Rome 00161, Italy.
A compact and robust optical excitation photoacoustic sensor with a self-integrated laser module excitation and an optimized differential resonator was developed to achieve high sensitivity and full linear range detection of carbon dioxide (CO) based on dual modes of wavelength modulated photoacoustic spectroscopy (WMPAS) and resonant frequency tracking (RFT). The integrated laser module equipped with three lasers (a quantum cascade laser (QCL), a distributed feedback laser (DFB) and a He-Ne laser) working in a time-division multiplexing mode was used as an integrated set of spectroscopic sources for detection of the designated concentration levels of CO. With the absorption photoacoustic mode, the WMPAS detection with the QCL and DFB sources was capable of CO detection at concentrations below 20 %, yielding a noise equivalent concentration (NEC) as low as 240 ppt and a normalized noise equivalent absorption coefficient (NNEA) of 4.
View Article and Find Full Text PDFMeasurement and validation of high-temperature CO spectral line parameters near 2.3 μm using TDLAS for combustion diagnostics.
Spectrochim Acta A Mol Biomol Spectrosc
December 2024
College of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou 221116, PR China. Electronic address:
Accurate determination of spectral parameters for carbon monoxide (CO) transitions is crucial for the development of laser absorption spectroscopy-based CO sensors. This study reports the measurement of line strengths, self-broadening coefficients, and their temperature-dependent exponents for three transitions in the first overtone band near 2.3 μm.
View Article and Find Full Text PDFExtended Short-Wave Infrared Colloidal Quantum Dot Lasers with Nanosecond Excitation.
Adv Mater
December 2024
ICFO, Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), 08860, Spain.
Solution-processed gain media have great technological potential as lasers due to their ease of integration with on-chip photonics, scalability and tuneable optoelectronic properties. Currently, the spectral coverage of solution-processed lasers extends from visible up to telecom wavelengths in the short-wave infrared (SWIR) (<1650 nm). Here, the optical gain in the extended SWIR from 1600 nm to 2500 nm is demonstrated, using PbSbased colloidal quantum dots (CQDs).
View Article and Find Full Text PDFTowards improved spectroscopic applications in multi-gas environments: CO spectral line parameter measurement and analysis.
Spectrochim Acta A Mol Biomol Spectrosc
March 2025
Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui 230031, China. Electronic address:
The ν + 2ν + ν band of CO is dominated by weak absorption lines near 2.0 uμm, which has potential application in planetary atmosphere, astrophysical, and hydrocarbon fuel combustion investigations. High-quality spectral line parameters are the foundation of spectroscopic technology.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!