Highly Tunable Room Temperature Quantum Cascade Lasers PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Highly Tunable Room Temperature Quantum Cascade Lasers PDF full book. Access full book title Highly Tunable Room Temperature Quantum Cascade Lasers by Fardeen Fraser Mackenzie. Download full books in PDF and EPUB format.
Author: Fardeen Fraser Mackenzie
Publisher:
ISBN:
Category : Electronics
Languages : en
Pages :
Get Book Here
Book Description
Author: Fardeen Fraser Mackenzie
Publisher:
ISBN:
Category : Electronics
Languages : en
Pages :
Get Book Here
Book Description
Author: Rowel Canaon Go
Publisher:
ISBN:
Category :
Languages : en
Pages : 35
Get Book Here
Book Description
A small sample of 2 cm2 size was taken from a 6-inch wafer and processed into ridge-waveguide chips 3 mm x 30 [micrometer] in size. Lateral current injection scheme was utilized due to an insulating M-buffer layer. Preliminary reliability testing up to 200 minutes of runtime showed no sign of power degradation. Laser chips with high reflection (HR) coating showed optical power over 200 mW of total peak power at cryogenic temperature (78 K), with lasing seen up to 230 K. In this temperature range, the measured characteristic temperatures of T0 ≈ 460 K and T1 ≈ 210 K describes the temperature dependence for threshold current and slope efficiency. Adding a partial HR coating (56%) on the front facet extended the lasing range above room temperature (303 K). This thesis will also discuss the preliminary cryogenic temperature result of the first InP-based QCL grown on latticemismatched silicon (Si) substrate.
Author: Dan Botez
Publisher: Cambridge University Press
ISBN: 1108570607
Category : Technology & Engineering
Languages : en
Pages : 552
Get Book Here
Book Description
Learn how the rapidly expanding area of mid-infrared and terahertz photonics has been revolutionized in this comprehensive overview. State-of-the-art practical applications are supported by real-life examples and expert guidance. Also featuring fundamental theory enabling you to improve performance of both existing and future devices.
Author: Jérôme Faist
Publisher: Oxford University Press
ISBN: 0198528248
Category : Science
Languages : en
Pages : 321
Get Book Here
Book Description
This book describes the physics, fabrication technology, and applications of the quantum cascade laser.
Author: Matthew Michael Suttinger
Publisher:
ISBN:
Category :
Languages : en
Pages : 95
Get Book Here
Book Description
Quantum Cascade Lasers are a novel semiconductor light source with the unique property of wavelength tunability over the mid-infrared and terahertz range of frequencies. Advances since their first demonstration in 1994 have led to highly efficient designs capable of continuous room temperature operation. In lieu of increased advances in laser core efficiency, power scaling with broad area quantum cascade lasers has demonstrated enhanced continuous power. This initial work is used as a starting point for continuing advances in average brightness of quantum cascade lasers. A figure of merit calculation reliably predicts to within parts in thousands the qualitative beam profile of continuously driven and high duty cycle devices. Further, a model is developed to project performance not only in continuously driven conditions, but also in variable duty cycles. This is combined with the figure of merit calculation to guide designs for optimized average brightness.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Author: Chun Wang Ivan Chan
Publisher:
ISBN:
Category :
Languages : en
Pages : 157
Get Book Here
Book Description
The as yet unattained milestone of room-temperature operation is essential for establishing Terahertz Quantum Cascade Lasers (THz QCLs) as practical sources of THz radiation. Temperature performance is hypothesized to be limited by upper laser level lifetime reduction due to non-radiative scattering, particularly by longitudinal optical phonons. To address this issue, this work studies highly "diagonal" QCLs, where the upper and lower laser level wave functions are spatially separated to preserve upper laser level lifetime, as well as several other issues relevant to high temperature performance. The highly diagonal devices of this work performed poorly, but the analysis herein nevertheless suggest that diagonality as a design strategy cannot yet be ruled out. Other causes of poor performance in the lasers are identified, and suggestions for future designs are made.
Author: Zhijun Liu
Publisher:
ISBN: 9780549513698
Category :
Languages : en
Pages : 296
Get Book Here
Book Description
Quantum Cascade (QC) lasers are mid-infrared semiconductor light sources which attract considerable interest for mid-infrared sensor systems, especially for high sensitivity and selectivity detection of chemical vapors in security, medical, and environmental applications. For some of these practical sensing applications, high temperature (room temperature and above), high power, continuous-wave (CW) operation is desirable for the purposes of simplifying the system and increasing the sensitivity. However, due to the thermal effects associated with the high threshold and low wall-plug efficiency, the performance of QC lasers is severely limited at high temperature. To overcome this problem, this dissertation shows how to optimize the QC laser performance through high gain active region and low loss waveguide designs, and advanced device processing and packaging for better thermal management.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Quantum cascade lasers are unipolar semiconductor lasers based on intersubband transitions in heterostructures. These lasers, which have demonstrated continuous wave operation at room temperature in the mid-infrared spectral range, are well suited for the realization of compact, ultra-sensitive, trace-gas sensors based on absorption spectroscopy. Up to now, only distributed feedback (DFB) single-mode devices have been used for such applications. DFB quantum cascade lasers have proven to be effective for gas sensing, but their relatively narrow tuning range, smaller or equal to about 1% of the wavelength, makes them not very versatile and limits their usefulness for spectroscopic investigations. In this thesis we developed broadly tunable external cavity quantum cascade lasers. The main advantage of these sources compared with DFBs is their broader tuning range, which is limited only by the spectral bandwidth of the gain element. We particularly studied broad gain bandwidth active regions based on bound-to-continuum designs. With that kind of active region, we have demonstrated a tuning range equal to 15% of the center wavelength at l ~ 10 mm, which was three times broader than the best values reported in the literature at that time, as well as good performance in pulsed mode at room temperature. Using a strain-compensated bound-to-continuum design emitting near 5.2 mm, we have demonstrated for the first time continuous-wave operation of an external cavity quantum cascade laser on a thermoelectric cooler. The tuning range was comparable to that of pulsed devices, but with a much better side-mode suppression ratio and a much narrower linewidth. This continuous-wave device has successfully been applied to the spectroscopy of nitric oxide in collaboration with Prof. Tittel's Laser Science Group at Rice University. High resolution absorption spectra of that gas could be acquired over a large wavelength range. We also studied heterogeneous cascade structures, that is quan.
Author: Aiting Jiang
Publisher:
ISBN:
Category :
Languages : en
Pages : 204
Get Book Here
Book Description
Terahertz Quantum Cascade Lasers (THz QCLs) and Terahertz Difference Frequency Generation Quantum Cascade Laser sources (DFG-QCLs) are two types of semiconductor THz radiation sources that are compact and amenable to production in mass quantities. THz QCL can generate over 1W of power under cryogenic temperatures, while THz DFG-QCL can be operated under room temperature over 1mW level output. For either case, widely tunable solution is highly desired for spectroscopy applications. For THz QCLs, operation is still limited to cryogenic temperature and broad tuning is not available. Our experimental study shows that using variable barriers is a viable approach to enhance the design space for THz QCLs. We also propose to tune the spectral output of these devices using an optically projected variable distributed feedback grating. Tuning will be achieved by changing the projected grating period. Preliminary experimental results support the idea but higher pumping light intensity is required for this method to work. For THz DFG-QCLs, very broad tuning in 1-6 THz range has been demonstrated using rotating diffraction grating in an external cavity setup. Similar tuning range can also be achieved in a monolithic configuration. Based on the previous work which demonstrated an electrical monolithic tuner with 580 GHz tuning range, we design and test in this dissertation a linear array of 10 DFG-QCL devices to cover a 2 THz tuning range. An independent gain control scheme is developed to achieve high yield (~100%) of individual device. It is implemented via independent current pumping of two electrically isolated sections. Surface DFB grating and independent current pumping scheme used in our DFG QCLs is found to be useful for mid-IR QCL array sources. We propose a longitudinal integration scheme of multiple grating sections. It enables a single ridge to emit single mode radiation at different wavelengths upon selection. This helps to reduce mid-IR QCL array far field span. We demonstrated single ridge devices that can emit 2 or 3 different wavelengths upon selection.
