Related Experiment Video
Updated: Aug 11, 2026
11:08
Fabrication And Characterization Of Photonic Crystal Slow Light Waveguides And Cavities
Published on: November 30, 2012
Frequency tuning of long-wavelength VCSELs
1Electrical and Computer Engineering Department, University of Alberta, 9107-116 Street, Edmonton, AB, Canada T6G 2V4. alytkine@ualberta.ca
Summary
This study experimentally tunes long-wavelength Vertical-Cavity Surface-Emitting Lasers (VCSELs). Faster tuning at higher direct current (dc) bias levels was observed, crucial for precise spectroscopic measurements.
Area of Science:
- Optoelectronics
- Laser Physics
- Spectroscopy
Background:
- Vertical-Cavity Surface-Emitting Lasers (VCSELs) are key components in optical systems.
- Understanding their tuning properties is essential for advanced applications.
- Long-wavelength VCSELs offer unique advantages for specific spectroscopic tasks.
Purpose of the Study:
- To experimentally investigate the tuning characteristics of long-wavelength VCSELs.
- To quantify the influence of injection current and temperature on laser frequency.
- To establish the applicability of these lasers in precise spectroscopic measurements.
Main Methods:
- Utilized a Fabry-Perot etalon to measure tuning rates of 1,512 nm and 1,577 nm VCSELs.
- Employed a 100-Hz saw-tooth modulation superimposed on direct current (dc) bias for fine spectral tuning.
- Approximated frequency tuning curves with a second-order polynomial.
Main Results:
- Observed faster tuning rates at higher dc bias levels, with enhancement factors up to 2 and 3 for the respective lasers.
- Demonstrated a linear dependence of injection current tuning rates on dc bias.
- Confirmed temperature tuning coefficients are independent of heat sink temperature and dc bias.
- Achieved an approximation accuracy within 0.2 cm⁻¹ for spectral intervals up to 38 cm⁻¹.
Conclusions:
- The tuning behavior of long-wavelength VCSELs is dependent on injection current and temperature.
- Accurate analysis of absorption line profiles requires consideration of current tuning rate dependence on dc bias.
- These findings enable precise spectroscopic measurements using long-wavelength VCSELs.
Related Concept Videos
01:07Effective Value of a Periodic Waveform
The concept of effective value, the root mean square (RMS) value, is crucial in understanding electrical circuits and power delivery. This idea emerges from the necessity to measure the effectiveness of a voltage or current source in supplying power to a resistive load.
The effective value of a periodic current represents the direct current (DC) that conveys the same average power to a resistor as the periodic current itself. This concept is crucial when assessing AC circuits. To determine the...
The effective value of a periodic current represents the direct current (DC) that conveys the same average power to a resistor as the periodic current itself. This concept is crucial when assessing AC circuits. To determine the...
01:31Oscillations In An LC Circuit
An idealized LC circuit of zero resistance can oscillate without any source of emf by shifting the energy stored in the circuit between the electric and magnetic fields. In such an LC circuit, if the capacitor contains a charge q before the switch is closed, then all the energy of the circuit is initially stored in the electric field of the capacitor. This energy is given by
01:22Intensity Of Electromagnetic Waves
The energy transport per unit area per unit time, or the Poynting vector, gives the energy flux of an electromagnetic wave at any specific time. For a plane electromagnetic wave with E0 and B0 as the peak electric and magnetic fields and traveling along the x-axis, the time-varying energy flux can be given by the following equation:
01:16UV–Vis Spectroscopy: Molecular Electronic Transitions
In Ultraviolet–Visible (UV–Vis) spectroscopy, the absorption of electromagnetic radiation is used to probe the electronic structure of molecules. This technique provides insights into molecular electronic transitions, particularly the movement of electrons between different molecular orbitals. Radiation is absorbed if the energy of the electromagnetic radiation passing through the molecule is precisely equal to the energy difference between the excited and ground states. During this process,...
01:02Ultraviolet and Visible (UV–Vis) Spectroscopy: Overview
Ultraviolet–visible (UV–visible or UV–Vis) spectroscopy is an analytical technique that investigates the interaction between matter and UV–Vis light within the electromagnetic spectrum. This method is widely used for its versatility, simplicity, and relatively quick data acquisition, making it valuable for both qualitative and quantitative analysis. When UV–Vis radiation passes through a material, molecules absorb light depending on the energy required for electronic transitions. As a result...