共查询到20条相似文献,搜索用时 437 毫秒
1.
We have developed 680-nm-band AlGalnP visible laser diodes having very lowintensity noise with stable self-sustained pulsation. The pulsation characteristics were affected by current spreading outside the ridge stripe. We obtained AlGalnP visible laser diodes with stable self-sustained pulsation by optimizing the ridge structure. The lasers achieved relative intensity noise (RIN) as low as-136 dB Hz–1 in the temperature range 20–50°C at 3 mW. 相似文献
2.
I. Matulková J. Cihelka J. Vysko?il Z. Zelinger E. Hulicius T. ?ime?ek S. Civi? 《Applied physics. B, Lasers and optics》2010,99(1-2):333-338
Vertical-Cavity Surface-Emitting Laser (VCSEL) diodes are among the youngest members of the semiconductor laser diode family. The main aim of our work focuses on the measurement of the basic properties (the spectral range of the laser emission, temperature and current tunability) of experimental VCSEL diode lasers based on GaSb operating in the infrared region around 4250 cm?1. A high-resolution FTIR Bruker IFS 120 HR spectrometer with a maximum resolution of 0.0035 cm?1 was used in the emission setup for the laser diagnostic research. The absorption spectra of atmospheric pollutants like methane, carbon monoxide and ammonia have been measured using these VCSELs for the first time. 相似文献
3.
K. Rßner M. Hümmer A. Benkert A. Forchel 《Physica E: Low-dimensional Systems and Nanostructures》2005,30(1-2):159-163
We have successfully fabricated and characterized room temperature continuous wave (cw) GaInAsSb/AlGaAsSb distributed feedback lasers emitting in the wavelength region between 2.499 and 2.573 μm. To the best of our knowledge, this is the longest emission wavelength realized with a GaSb-based DFB laser diode. The laser structure used for DFB processing was grown by solid source molecular beam epitaxy. A DFB concept requiring no subsequent overgrowth step was used by defining first-order Cr-Bragg gratings laterally patterned to a ridge waveguide. Threshold currents smaller than 60 mA and room temperature cw output powers up to 6.5 mW were obtained. The laser diodes show single mode emission with side mode suppression ratios (SMSR) of up to 32 dB. 相似文献
4.
Thermal properties of vertical-cavity surface-emitting lasers (VCSELs) are studied using their comprehensive, three-dimensional,
self-consistent, thermal-electrical simulation. The thermal resistance versus operation current relation is found to be completely
different for two basic VCSEL configurations, i.e. for proton-implanted top-surface-emitting lasers (top-emitting VCSELs)
and etched-well lasers (bottom-emitting VCSELs). The above fact is explained using a concept of the average centre of heat
generation within a laser volume and its shift with an increase in an operation current.
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
5.
Wen-Shing Tsai Shah-Jye Tzeng Shih-Hung Chen Tzu-Shen Chien 《Optics Communications》2006,263(2):201-206
A bidirectional hybrid dense-wavelength-division-multiplexing (DWDM)-passive optical network (PON) employing optical injection locking technique on vertical-cavity surface-emitting lasers (VCSELs) and data comparator, as well as optical injection locking technique on distributed feedback laser diodes (DFB LDs) and amplitude/phase compensator is proposed and demonstrated. Improved performances of bit error rate (BER) and carrier-to-noise ratio/composite second order/composite triple beat (CNR/CSO/CTB) were observed in our proposed bidirectional hybrid DWDM-PON. Bidirectional transmission in bidirectional hybrid DWDM-PON architecture is a very attractive option, the capacity of the optical network can be expanded relatively easily by bidirectional transmission technology. 相似文献
6.
Guoen Weng Shaoqiang Chen Yang Mei Yuejun Liu Hidefumi Akiyama Xiaobo Hu Jianping Liu Baoping Zhang Junhao Chu 《Annalen der Physik》2020,532(1):1900308
Dual-wavelength lasing operations are demonstrated in GaN-based vertical-cavity surface-emitting lasers (VCSELs) comprising ingeniously designed asymmetric InGaN quantum wells (AS-QWs). The dual laser modes show exact positive-correlated polarization dependences with a high degree of polarization of up to 98%. By simply tuning the pump energy, the components and intensity of the laser outputs can be continuously changed, making wavelength selection and switching available for the GaN-based VCSELs. Detailed theoretical analysis and experimental measurements show that the intensity of optical gain and the coupling between the active layer and optical field, namely the electron–photon interaction, as well as carrier tunneling and photon reabsorption play a crucial role in the multiwavelength lasing processes. Moreover, the design principles of the proposed AS-QWs and multistacked size-varied quantum dot (MS-QD) active regions are elaborated to provide guidelines for controllable multiwavelength emissions in GaN-based surface-emitting lasers. These results not only provide better understanding of lasing in nitride-based microcavity systems but also shed insight into the more fundamental issues of electron–photon coupling in such systems. Importantly, such controllable multiwavelength laser operations may extend nitride-based VCSELs to previously inaccessible areas, for example, flip-flop, ultrafast switches, and other functional devices such as Raman lasers and sensors. 相似文献
7.
We numerically investigate the effects of parameter mismatches on chaos synchronization in vertical-cavity surfaceemitting lasers (VCSELs). We assume injection-locked chaos synchronization in a unidirectionally coupled and openloop optical feedback system. The accuracy of chaos synchronization is greatly affected by the mismatches of the device parameters and operation conditions between the two lasers. In particular, the oscillation frequency of the laser is one of the important parameters in a system of injection-locked chaos synchronization. However, the variations of the device characteristics of VCSELs are very large compared with those of other types of semiconductor lasers. We study the effects of parameter mismatches related to the oscillation frequency of VCSELs on chaos synchronization. We proved that mismatches in terms of the birefringence and the injection current play crucial roles for the quality of chaos synchronization. 相似文献
8.
R. Engelbrecht B. Lins P. Zinn R. Buchtal B. Schmauss 《Applied physics. B, Lasers and optics》2012,109(3):441-452
Laser diode line widths and line shapes are experimentally investigated in dependence on the diode current and on back reflections from an optical system. Four distributed-feedback (DFB)-type diode lasers and two vertical-cavity surface-emitting lasers (VCSELs) have been tested within the same optical setup and using the same fitting methods. System back reflection ratios of light reflected back to the laser have been varied between ?1?dB and ?45?dB and were below ?60?dB when all reflections were blocked. The background of this investigation is the evaluation of different laser types with respect to their suitability for sensor applications in which optical back reflections may occur, for example tunable diode-laser spectroscopy (TDLS). While DFB-type lasers showed almost pure Lorentzian line shapes and line widths of a few MHz, the tested VCSELs had a strong Gaussian contribution to the line shape, indicating stronger 1/f noise, which was also observed in the relative intensity noise of these particular lasers. System reflection ratios above ?25?dB had strong effects on the line width in both DFB diode lasers and VCSELs, while some influences have been observed at even lower reflection ratios for DFB diode lasers. As much smaller reflection ratios are typically required in TDLS systems to avoid etalon-like fringes and self-mixing interference effects, we conclude that the influence on the line width is not the most important reason to minimize back reflections in practical TDLS systems or to choose one type of diode laser over the other. 相似文献
9.
Excitation of various transverse modes in possible nitride vertical-cavity surface-emitting lasers (VCSELs) is investigated and compared using the effective frequency optical model. In the comparative analysis of laser mode selectivity, two distinctly different configurations of possible nitride VCSELs are considered: the traditional VCSEL design with both (n-side and p-side) ring contacts as well as the uniform-current-injection (UCI) VCSEL design. Our simulation reveals that, during the continuous-wave device operation at room temperature, a multi-mode operation dominated by higher-order transverse modes is typical for traditional nitride VCSEL configurations whereas a desirable single-mode (based on the fundamental LP01 mode) operation turns out to be characteristic for the wide current range in UCI ones. The above different threshold device behaviours are an immediate consequence of essentially different current-spreading phenomena in both VCSEL designs, resulting in completely different not only gain profiles but also temperature distributions within the laser active regions of both VCSELs. Seemingly similar behaviour has been also reported in arsenide VCSELs but it is expected to be much more severe in the case of nitride ones as a result of much higher both electrical resistivities of p-type nitrides and their temperature derivatives of refractive indices. 相似文献
10.
Three types of lasers (double-heterostructure 66 K InAsSb/InAsSbP laser diode, room temperature, multi quantum wells with
distributed feedback (MQW with DFB) (GaInAsSb/AlGaAsSb based) diode laser and vertical cavity surface emitting lasers (VCSELs)
(GaSb based) have been characterized using Fourier transform emission spectroscopy and compared. The photoacoustic technique
was employed to determine the detection limit of formaldehyde (less than 1 ppmV) for the strongest absorption line of the
v3 + v5 band in the emission region of the GaInAsSb/AlGaAsSb diode laser. The detection limit (less than 10 ppbV) of formaldehyde
was achieved in the 2820 cm−1 spectral range in case of InAsSb/InAsSbP laser (fundamental bands of v1, v5). Laser sensitive detection (laser absorption together with high resolution Fourier transform infrared technique including
direct laser linewidth measurement, infrared photoacoustic detection of neutral molecules (methane, form-aldehyde) is discussed. 相似文献
11.
We theoretically investigate the synchronization performance of the polarization modes of two unidirectionally coupled vertical-cavity surface-emitting lasers (VCSELs), where the master VCSEL subjects to polarization-preserved optical feedback and the slave VCSEL subjects to polarization-preserved optical injection. We demonstrate that high synchronization can be achieved between corresponding polarization components of the master laser and the slave laser. We also analyze the influence of the internal mismatched parameters on the synchronization performance. Furthermore, this system is used to dual-channel communication and the different transmitted digital information is respectively recovered at each polarization branch of the slaver laser successfully with the encryption scheme of chaos masking (CM). The results open an opportunity for multichannel chaotic communication by utilizing different polarization components in single-mode or multi-transverse-mode VCSELs. 相似文献
12.
Analytical modelling of end thermal coupling in a solid-state laser longitudinally bonded by a vertical-cavity top-emitting laser diode 下载免费PDF全文
The intrinsic features involving a circularly symmetric beam
profile with low divergence, planar geometry as well as the increasingly
enhanced power of vertical-cavity surface-emitting lasers (VCSELs)
have made the VCSEL a promising pump source in direct end bonding to
a solid-state laser medium to form the minimized, on-wafer
integrated laser system. This scheme will generate a surface contact
pump configuration and thus additional end thermal coupling to the
laser medium through the joint interface of both materials, apart from
pump beam heating. This paper analytically models temperature
distributions in both VCSEL and the laser medium from the end thermal
coupling regarding surface contact pump configuration using a
top-emitting VCSEL as the pump source for the first time. The
analytical solutions are derived by introducing relative temperature
and mean temperature expressions. The results show that the end
contact heating by the VCSEL could lead to considerable temperature
variations associated with thermal phase shift and thermal lensing
in the laser medium. However, if the central temperature of the
interface is increased by less than 20~K, the end contact heating
does not have a significant thermal influence on the laser medium. In
this case, the thermal effect should be dominated by pump beam
heating. This work provides useful analytical results for further
analysis of hybrid thermal effects on those lasers pumped by a direct
VCSEL bond. 相似文献
13.
High-performance InGaAs/InGaAlAs multiple-quantum-well vertical-cavity surface-emitting lasers (VCSELs) with InGaAlAs/InP distributed Bragg reflectors are proposed for operation at the wavelength of 1.55 μm. The lasers have good heat diffusion characteristic, large index contrast in DBRs, and weak temperature sensitivity. They could be fabricated either by metal-organic chemical vapor deposition (MOCVD) or by molecular beam epitaxy (MBE) growth. The laser light-current characteristics indicate that a suitable reflectivity of the DBR on the light output side in a laser makes its output power increase greatly and its lasing threshold current reduce significantly, and that a small VCSEL could output the power around its maximum for the output mirror at the reflectivity varying in a broader range than a large VCSEL does. 相似文献
14.
Wavelength stabilization and spectrum narrowing of high-power multimode laser diodes and arrays by use of volume Bragg gratings 总被引:15,自引:0,他引:15
Spectral line narrowing (by a factor of 8) and stabilization of the emission wavelength (by a factor of 30) of multimode high-power laser diodes and arrays is demonstrated by use of volume Bragg gratings fabricated in high-stability inorganic photorefractive glasses. Applications include stabilization of pump laser diodes and arrays for solid-state lasers and metal-vapor lasers, spin hyperpolarization of noble gases used in medical imaging, and others. 相似文献
15.
16.
S. K. Yang J. S. Yu S. H. Lee Y. T. Ko T. I. Kim 《Optical and Quantum Electronics》1995,27(5):447-451
A novel self-align method has been developed for the fabrication of 980 nm ridge waveguide laser diodes. It utilizes the facts that (1) the thickness of photoresist on the ridge top is substantially less than that in its vicinity and (2) their respective exposure times differ accordingly. Except for replacing the second photolithographic step with a simple flood-exposure, the fabrication procedure is identical to that for conventional ridge waveguide laser diodes. No additional materials or processing steps are required. As a result, the laser fabrication is significantly simplified with excellent reproducibility. 相似文献
17.
18.
Ning CZ 《Optics letters》2002,27(11):912-914
We demonstrate that high-frequency, narrow-band, self-pulsating intensity oscillation can be generated with two coupled vertical-cavity surface-emitting lasers (VCSELs) and that such oscillation is greatly enhanced by collecting one of the two field lobes. The coupled VCSELs provide an ideal source for high-repetition-rate (over 40 GHz), sinusoidallike modulated laser light with Gaussian-like near- and far-field profiles. We also show that the modulation frequency can be tuned by inter-VCSEL separation or by a dc bias level. 相似文献
19.
设计出四次质子注入工艺制备垂直腔面发射激光器(VCSEL)阵列的方法,实现了对阵列中单元器件间的隔离以及对单元器件注入电流限制的分别作用。一方面通过对VCSEL外延片上分布布拉格反射镜(DBR)两次较浅的质子注入形成高电阻区域实现对阵列中单元器件间的隔离,另一方面通过再次的两次较深度的可以达到有源区上表面的质子注入形成高电阻区域实现对单元器件注入电流的限制。由瞬态热传导方程对阵列中单元器件间的热相互作用进行了理论分析。采用四次质子注入工艺实现了2×2、3×3简单的二维GaAs/AlGaAs量子阱VCSEL阵列,并对器件的激射近场、光谱特性及功率等进行了测量。 相似文献
20.
W. Nakwaski 《Optical and Quantum Electronics》1996,28(4):335-352
Thermal aspects of efficient operation of vertical cavity surface-emitting lasers (VCSELs) are reviewed and discussed. The effects of temperature on VCSEL operation characteristics are considered, including the temperature dependence of their longitudinal mode spectra, their threshold current, and their transverse-mode structure. The principles of operation of temperature-insensitive VCSELs are explained.A comparison between the behaviour of VCSELs and that of conventional edgeemitting lasers is emphasized. 相似文献