https://photonica.io Practical photonics engineering — tutorials, references, and tools. en-us Wed, 20 May 2026 00:00:00 GMT https://photonica.io/articles/photodetector-characterization https://photonica.io/articles/photodetector-characterization Wed, 20 May 2026 00:00:00 GMT Procedures for measuring the three primary parameters of photodetectors used in photonics — wavelength-dependent responsivity, noise-equivalent power, and 3-dB electrical bandwidth — with focus on the standard measurement configurations for InGaAs PIN photodiodes. Procedure · Detector characterization https://photonica.io/articles/dfb-characterization-workflow https://photonica.io/articles/dfb-characterization-workflow Tue, 19 May 2026 00:00:00 GMT Complete characterization workflow for a distributed-feedback (DFB) semiconductor laser, integrating LIV, spectral, temperature-dependent, and noise measurements to extract the parameters required for telecom and sensing applications. Workflow · Laser characterization https://photonica.io/articles/optical-spectrum-analyzer-fundamentals https://photonica.io/articles/optical-spectrum-analyzer-fundamentals Mon, 18 May 2026 00:00:00 GMT Reference for optical spectrum analyzers (OSAs) including diffraction grating, Fabry-Pérot, and Fourier-transform variants, resolution bandwidth and dynamic range specifications, and the standard measurement configurations for laser source characterization, OSNR measurement, and EDFA gain characterization. Reference · Instrumentation https://photonica.io/articles/wall-plug-efficiency-from-liv https://photonica.io/articles/wall-plug-efficiency-from-liv Sun, 17 May 2026 00:00:00 GMT Procedure for computing wall-plug efficiency (electrical-to-optical conversion efficiency) of a semiconductor laser from LIV data, with discussion of peak operating point, comparison with internal and external quantum efficiencies, and typical values across device classes. Procedure · Laser characterization https://photonica.io/articles/laser-characterization-bench-setup https://photonica.io/articles/laser-characterization-bench-setup Sat, 16 May 2026 00:00:00 GMT Equipment selection, thermal mounting, electrical configuration, and noise mitigation for a benchtop laser diode characterization setup, with focus on the configuration choices that determine measurement quality. Procedure · Laser characterization https://photonica.io/articles/edge-coupler-alignment https://photonica.io/articles/edge-coupler-alignment Fri, 15 May 2026 00:00:00 GMT Procedure for alignment of optical fiber to edge coupler structures on photonic integrated circuits using lensed fibers and inverse-taper couplers, with discussion of butt-coupling, anti-reflection cleaving, and the distinct failure modes compared to grating coupler alignment. Procedure · PIC characterization https://photonica.io/articles/pulsed-vs-cw-liv-measurement https://photonica.io/articles/pulsed-vs-cw-liv-measurement Thu, 14 May 2026 00:00:00 GMT Comparison of pulsed and continuous-wave measurement modes for semiconductor laser LIV characterization, with quantification of self-heating bias, duty cycle requirements, and equipment configuration. Procedure · Laser characterization https://photonica.io/articles/threshold-extraction-methods https://photonica.io/articles/threshold-extraction-methods Wed, 13 May 2026 00:00:00 GMT Comparison of the four standard methods for extracting threshold current from a semiconductor laser LIV curve, applied to a single dataset, with discussion of when each method is preferred and the systematic differences between them. Procedure · Laser characterization https://photonica.io/articles/m2-beam-quality-measurement https://photonica.io/articles/m2-beam-quality-measurement Tue, 12 May 2026 00:00:00 GMT Procedure for measuring the M² beam quality parameter of a laser beam using the knife-edge method per ISO 11146-1, including hyperbolic fitting, the D4σ width definition, and the dominant sources of measurement error. Procedure · Laser characterization https://photonica.io/articles/rin-measurement https://photonica.io/articles/rin-measurement Mon, 11 May 2026 00:00:00 GMT Procedure for measuring relative intensity noise (RIN) of a semiconductor laser using direct detection and an electronic spectrum analyzer, including shot-noise calibration, detector and electronic noise subtraction, and common measurement errors. Procedure · Laser characterization https://photonica.io/articles/ring-resonator-q-extraction https://photonica.io/articles/ring-resonator-q-extraction Sun, 10 May 2026 00:00:00 GMT Procedure for extracting loaded and intrinsic quality factors of integrated ring resonators from measured transmission spectra, including fit methodology, the all-pass / add-drop distinction, and resolution of the coupling regime ambiguity. Procedure · PIC characterization https://photonica.io/articles/cutback-propagation-loss https://photonica.io/articles/cutback-propagation-loss Sat, 09 May 2026 00:00:00 GMT Procedure for measuring optical propagation loss in integrated photonic waveguides using the cutback method, including paired-device variants used in foundry process control, fit methodology, and uncertainty analysis. Procedure · PIC characterization https://photonica.io/articles/slope-efficiency-extraction https://photonica.io/articles/slope-efficiency-extraction Fri, 08 May 2026 00:00:00 GMT Procedure for extracting slope efficiency and external differential quantum efficiency from laser diode LIV data, with discussion of measurement geometry, facet-collection considerations, and common extraction errors. Procedure · Laser characterization https://photonica.io/articles/extracting-t0-from-liv-measurements https://photonica.io/articles/extracting-t0-from-liv-measurements Thu, 07 May 2026 00:00:00 GMT Procedure for extracting the characteristic temperature T₀ of a semiconductor laser diode from temperature-dependent threshold current measurements, with worked example and discussion of extraction errors. Procedure · Laser characterization https://photonica.io/articles/first-light-grating-coupler-alignment https://photonica.io/articles/first-light-grating-coupler-alignment Tue, 05 May 2026 00:00:00 GMT Procedure for obtaining initial optical coupling between a single-mode fiber and a surface grating coupler on a silicon photonic integrated circuit, including equipment requirements, search algorithm, expected losses, and common failure modes. Procedure · PIC characterization