| 1. |
- Chitica, N, et al.
(author)
-
Fabrication of tunable InP/air-gap Fabry-Perot cavities by selective etching of InGaAs sacrificial layers
- 1999
-
In: Physica scripta. T. - : ROYAL SWEDISH ACAD SCIENCES. - 0281-1847. ; T79, s. 131-134
-
Journal article (peer-reviewed)abstract
- We report the fabrication of InP/air-gap Fabry-Perot resonant cavities with an improved tunability characteristic achieved through the micromachining of more flexible suspended InP beams. The micromechanical structures are electrostatically actuated. A tuning range of 55 nm is demonstrated for an actuation voltage of 12 V. The low leakage current, of less than 10 µA for a bias of up to 30 V, provides a low actuation power. The tunable air-gap cavities are fabricated by selective wet etching of InGaAs sacrificial layers. An FeCl3 based etchant is used to completely remove the InGaAs material without affecting the thickness of the InP layer. The anisotropy of the etch rate of InGaAs was also investigated and exploited in the micromachining process.
|
|
| 2. |
- Strassner, Martin, et al.
(author)
-
1.55 mu m VCSELs with InP/air-gap distributed bragg reflectors
- 2004
-
In: 2004 International Conference on Indium Phosphide and Related Materials, Conference Proceedings. - 0780385950 ; , s. 700-703
-
Conference paper (peer-reviewed)abstract
- The presented VCSELs demonstrate the possibility of fabricating cavities with extremely large Q-factors by using InP/air-gap DBRs. At the same time, the deployed technologies permits to fabricate potentially tunable VCSELs. Photo-pumped and electrically pumped VCSELs and their tunability when working as resonant cavity light emitting diodes are presented. Output powers of up to I 10 mu W at room temperature and a maximum wavelength tuning of 22 nm have been achieved.
|
|
| 3. |
- Di Fatta, G., et al.
(author)
-
Preface
- 2011
-
In: IEEE International Conference on Data Mining. Proceedings. - : Institute of Electrical and Electronics Engineers (IEEE). - 1550-4786. ; , s. xlviii-xlvix
-
Journal article (peer-reviewed)
|
|
| 4. |
- Hillmer, H., et al.
(author)
-
Wide continuously tunable 1.55 μm vertical air-cavity wavelength selective elements for filters and VCSELs using micromachined actuation
- 2005
-
In: Opto-Ireland 2005. - : SPIE - International Society for Optical Engineering. - 0819458104 ; , s. 14-28
-
Conference paper (peer-reviewed)abstract
- Tailored scaling allows the effectiveness of physical effects and mechanical stability to be enhanced. This is shown for micromachined 1.55μm vertical-resonator-based filters and VCSELs, capable of wide, continuous, and kink-free tuning by a single control parameter. Tuning is achieved by mechanically actuating one or several membranes in a vertical air-gap resonator including two highly reflective DBR mirrors. Electrostatically actuatable single-chip filters including InP/air-gap DBR's (3.5 periods) reveal a continuous tuning up to 14% of the absolute wavelength. Varying a reverse voltage (U=0 .. -3.2V) between the membranes (almost flat in the unactuated condition) a tuning range up to 142nm was obtained. Varying a reverse voltage (U=0 .. -28V) between the membranes (strained and curved in the unactuated condition) a tuning range up to 221nm was obtained. Optically pumped and continuously tunable 1.55μm VCSELs show 26nm spectral tuning range, 400μW maximum output power, and 57dBm SMSR. This two-chip VCSEL has a movable top mirror membrane, which is precisely designed to obtain a specific air-gap length and a tailored radius of curvature in order to efficiently support the fundamental optical mode of the plane-concave resonator. The curved top mirror DBR membrane consists of periodically alternating differently stressed silicon nitride and silicon dioxide multilayers. The lower InP-based part consists of the InP/GaInAsP bottom DBR and the GaInAsP active region.
|
|
| 5. |
- Lindberg, H., et al.
(author)
-
Optically pumped VECSEL operating at 1550 nm
- 2004
-
In: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. ; , s. 25-33
-
Conference paper (peer-reviewed)abstract
- We present the design and characteristics of an optically pumped vertical external cavity surface emitting laser emitting near 1550 nm. The InP-based laser was grown by Metalorganic vapor-phase epitaxy including an InGaAsP gain element and an InP/InGaAsP mirror. The gain element comprises 20 strain compensated quantum wells on top of a distributed Bragg reflector. As an external mirror we used a concave spherical mirror, which also provides the outcoupling of light. Gain is achieved by optical pumping with a high power, 1250 nm fiber Raman laser focused on the gain chip. Essential for achieving high output power is to reduce the temperature of the gain material and this is accomplished by bonding an intra-cavity silicon heat spreader to the surface of the gain element. The maximum output power is 260 mW at multi transverse mode operation and 230 mW at single transverse mode operation with a near Gaussian beam profile (M2=1.22) at 240 K. At room temperature the output power was limited to 12 mW. The maximum output power greatly depends on the operating temperature and studies of pump induced thermal effects show that thermal lensing imposes limitations on the attainable power.
|
|
| 6. |
- Lindberg, H., et al.
(author)
-
Thermal management of optically pumped long-wavelength InP-based semiconductor disk lasers
- 2005
-
In: IEEE Journal of Selected Topics in Quantum Electronics. - 1077-260X .- 1558-4542. ; 11:5, s. 1126-1134
-
Journal article (peer-reviewed)abstract
- We have developed a numerical model for investigating material heating and its effects on the performance of optically pumped InP-based long-wavelength semiconductor disk lasers. Material heating and optical wavefront distortion due to thermal lensing are analyzed, and different approaches to reduce the intrinsic material heating are investigated numerically and experimentally. The results obtained indicate that material heating is significant in such lasers due to the poor thermal properties of the InP-based epitaxial layers of the gain chip. Substrate removal is shown to be an insufficient method to reduce the material heating; instead, crystalline heat spreaders bonded to the gain chip surface provide a convenient way to reduce the thermal impedance. Important parameters for such heat spreaders are a high thermal conductivity and a low thermooptic coefficient (dn / dT). With the use of a synthetic diamond heat spreader, a maximum pump limited output power of 780 mW in a near diffraction limited beam (M-2 < 1.2) was demonstrated at - 33 degrees C and 100 mW at room temperature.
|
|
| 7. |
- Strassner, M, et al.
(author)
-
III-V semiconductor material for tunable Fabry-Perot filters for coarse and dense WDM systems
- 2000
-
In: SENSORS AND ACTUATORS A-PHYSICAL. - : ELSEVIER SCIENCE SA. - 0924-4247. ; 85:1-3, s. 249-255
-
Journal article (peer-reviewed)abstract
- In the following payer, we report on the investigation of the mechanical properties of InP grown on InGaAs by organic metal vapor phase epitaxy (OMVPE). When InP is grown, it is stressed due to an unintentional arsenic doping profile. This stress gradient
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
- Symonds, Clémentine, et al.
(author)
-
High performance 1.55μm vertical external cavity surface emitting laser with broadband integrated dielectric-metal mirror
- 2004
-
In: Electronics Letters. - : Institution of Engineering and Technology (IET). - 0013-5194 .- 1350-911X. ; 40:12, s. 734-735
-
Journal article (peer-reviewed)abstract
- 1.55 μm room-temperature continuous-wave operation of a high performance optically pumped vertical external cavity surface emitting laser is reported. The structure includes an active region with strain compensated quantum wells, and a broadband SiNx/Si/Au Bragg reflector transferred on an Si substrate by Au/In dry bonding. Output power of up to 45 mW is achieved at 0°C, and continuous-wave operation is observed up to 45°C.
|
|
