How exact are simplified scalar approaches to optical fields in oxide-confined stripe-geometry diode lasers?

2007 ◽  
Vol 15 (2) ◽  
Author(s):  
T. Czyszanowski ◽  
W. Nakwaski
Keyword(s):  
Diode Laser ◽  
Diode Lasers ◽  
Method Of Lines ◽  
Computation Time ◽  
Laser Cavity ◽  
Lasing Threshold ◽  
Optical Fields ◽  
Index Method ◽  
Effective Index Method

AbstractOptical model, scalar or vectorial one, describing behaviour of an optical field within a diode-laser cavity, is one of the most important parts of modelling of a diode-laser operation. As compared to more accurate vectorial optical approaches, scalar ones are known to be less exact but simultaneously they need much less computation time. Besides, they have been sometimes found to be surprisingly exact even beyond their confirmed range of validity. Therefore, in this paper, real validity limits of their application have been determined by comparing their simplified results with more exact results obtained with the aid of vectorial models. The analysis comprises a comparison of an application of the most popular scalar approach to optical properties of diode lasers, i.e., the effective index method, and the vectorial method of lines for the standard 1.3-µm GaAs-based stripe-geometry diode laser. The scalar model has been found to be quite exact in the case of a determination of the effective refractive index, i.e., the wavelength of emitted radiation, whereas its exactness in the lasing threshold analysis is much worse, especially in the case of higher-order modes. Our analysis is concluded with a determination of the regions where both models give satisfactorily close results.

Application of Diode Lasers in Interferometrical Length Measurements

2010 ◽  
Vol 437 ◽  
pp. 423-427 ◽  
Author(s):  
Alexander Höink ◽  
Karl Meiners-Hagen ◽  
Otto Jusko ◽  
Ahmed Abou-Zeid
Keyword(s):  
Diode Laser ◽  
Diode Lasers ◽  
Experimental Results ◽  
Length Measurements ◽  
Multi Wavelength ◽  
Different Diameters ◽  
Laser Interferometers

The experimental results for the determination of the form of thin cylinders (Ø ~ 2.5 mm) as well as step heights of gauge blocks (~ 100 µm) and roundness profiles of test samples from metal or glass with different diameters between ~ 2.5 mm and 80 mm using two multi-wavelength diode laser interferometers are presented and discussed.

scholarly journals Analytic Modeling of Trench Waveguides for Channel Plasmon-Polariton Using Full-Hybrid Trial-Field Functions

ISRN Optics ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Sujit Chattopadhyay ◽  
Pradip Kumar Saha
Keyword(s):  
Rectangular Cross Section ◽  
Propagation Constant ◽  
Method Of Lines ◽  
Effective Index ◽  
Index Method ◽  
Effective Index Method ◽  
Trial Field ◽  
Complex Propagation ◽  
Plasmon Polariton ◽  
Hybrid Trial

A full-hybrid trial-field modeling, which was proposed earlier by the authors for plasmonic structures of rectangular cross-section, has been applied to trench waveguides for channel plasmon polariton. Most of the computed results of complex propagation constant agree well with those obtained by method of lines and effective index method, though the latter two results themselves show some discrepancy. The particular aspect in which there is varying degree of disagreement among the results obtained in the above three methods is the imaginary part of the effective index seen by the plasmon-polariton.

scholarly journals Determination of Potential Profile In Planar Electronic Structures Using A Semi-Analytical Technique

2010 ◽  
Vol 7 (1) ◽  
pp. 62
Author(s):  
Hadj Bourdoucen ◽  
Mokrane Dehmas ◽  
El-Bachir Yallaoui
Keyword(s):  
Electronic Structures ◽  
Semiconductor Device ◽  
Method Of Lines ◽  
Computation Time ◽  
Potential Profile ◽  
Voltage Profile ◽  
Analytical Technique ◽  
The Method Of Lines ◽  
Discretization Schemes

 In this paper, a semi-analytical technique known as the Method of Lines (MoL) with uniform and non-uniform discretization schemes is developed. The aim is to determine static potential profile in planar electronic structures. Even though this method has been known for some time, there has been reported work on its application to planar semiconductor device analysis for voltage profile determination. Since most current electronic devices are manufactured using planar and quasi-planar technology, the proposed algorithm is well suited for device analysis prior to fabrication. Compared with known popular methods such as Finite Difference and Finite Elements methods, the proposed technique is relatively simple, more accurate and unlike other methods, has no convergence problem. In addition to this, its semi-analytical nature, which consists of reducing one computing dimension, allows saving significant memory and computation time. Typical planar electronic structures are considered to demonstrate their suitability for these devices, and the obtained results are presented and discussed. 

Structure optimisation of short-wavelength ridge-waveguide InGaN/GaN diode lasers

2008 ◽  
Vol 16 (1) ◽  
Author(s):  
P. Karbownik ◽  
R. Sarzała
Keyword(s):  
Active Region ◽  
Diode Laser ◽  
Temperature Increase ◽  
Room Temperature ◽  
Continuous Wave ◽  
Diode Lasers ◽  
Ridge Waveguide ◽  
Lasing Threshold ◽  
Etching Depth ◽  
Region Temperature

AbstractRoom-temperature (RT) continuous-wave (CW) operation of the 405-nm ridge-waveguide (RW) InGaN/GaN quantum-well diode lasers equipped with the n-type GaN substrate and two contacts on both sides of the structure has been investigated with the aid of the comprehensive self-consistent simulation model. As expected, the mounting configuration (p-side up or down) has been found to have a crucial impact on the diode laser performance. For the RT CW threshold operation of the otherwise identical diode laser, the p-side up RW laser exhibits as high as nearly 68°C maximal active-region temperature increase whereas an analogous increase for the p-side down laser was equal to only 24°C. Our simulation reveals that the lowest room-temperature lasing threshold may be expected for relatively narrow and deep ridges. For the structure under consideration, the lowest threshold current density of 5.75 kA/cm2 has been determined for the 2.2-μm ridge width and the 400-nm etching depth. Then, the active-region temperature increase was as low as only 24 K over RT. For wider 5-μm ridge, this increase is twice higher. An impact of etching depth is more essential for narrower ridges. Quite high values (between 120 and 140 K) of the characteristic parameter T0 convince very good thermal properties of the above laser.

scholarly journals Theoretical Analysis of Terahertz Dielectric–Loaded Graphene Waveguide

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 210
Author(s):  
Da Teng ◽  
Kai Wang
Keyword(s):  
Photonic Devices ◽  
Effective Index ◽  
The Finite Element Method ◽  
Index Method ◽  
Modal Properties ◽  
Terahertz Region ◽  
Effective Index Method ◽  
Integration Density ◽  
Device Integration ◽  
Potential Applications

The waveguiding of terahertz surface plasmons by a GaAs strip-loaded graphene waveguide is investigated based on the effective-index method and the finite element method. Modal properties of the effective mode index, modal loss, and cut-off characteristics of higher order modes are investigated. By modulating the Fermi level, the modal properties of the fundamental mode could be adjusted. The accuracy of the effective-index method is verified by a comparison between the analytical results and numerical simulations. Besides the modal properties, the crosstalk between the adjacent waveguides, which determines the device integration density, is studied. The findings show that the effective-index method is highly valid for analyzing dielectric-loaded graphene plasmon waveguides in the terahertz region and may have potential applications in subwavelength tunable integrated photonic devices.

scholarly journals Medical Applications of Diode Lasers: Pulsed versus Continuous Wave (cw) Regime

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 710
Author(s):  
Michał Michalik ◽  
Jacek Szymańczyk ◽  
Michał Stajnke ◽  
Tomasz Ochrymiuk ◽  
Adam Cenian
Keyword(s):  
Diode Laser ◽  
Continuous Wave ◽  
Diode Lasers ◽  
Short Review ◽  
Medical Application ◽  
Medical Applications ◽  
Therapeutic Effects ◽  
Pulsed Mode ◽  
Medical Therapies

The paper deals with the medical application of diode-lasers. A short review of medical therapies is presented, taking into account the wavelength applied, continuous wave (cw) or pulsed regimes, and their therapeutic effects. Special attention was paid to the laryngological application of a pulsed diode laser with wavelength 810 nm, and dermatologic applications of a 975 nm laser working at cw and pulsed mode. The efficacy of the laser procedures and a comparison of the pulsed and cw regimes is presented and discussed.

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