共查询到20条相似文献,搜索用时 46 毫秒
1.
Y. Gottesman E.V.K. Rao D. Piot E. Vergnol B. Dagens 《Applied physics. B, Lasers and optics》2001,73(5-6):609-612
This paper describes a comprehensive report on the high potential of optical low-coherence reflectometry (OLCR) measurements
to assist the design optimization and performance evaluation of symmetric MMI couplers. Using three sets of deep-ridge InGaAsP–InP
couplers on InP and by performing OLCR measurements simultaneously in reflection and transmission modes, the nature and origin
of all reflections in MMI have first been identified with respect to a deliberately chosen design parameter, namely, the coupler
length. In addition, and in total agreement with the self-imaging principle and also the BPM simulations, the back reflections
in combiner mode are shown to be prominent even in fully optimized devices. Finally, a simple design artifact has been proposed
and demonstrated experimentally for the first time to suppress back reflections.
Received: 16 May 2001 / Published online: 2 November 2001 相似文献
2.
We present comparative measurements of two Mach–Zehnder interferometers, one with Y-junction couplers and the other with MMI couplers, both developed in silicon-on-insulator technology and using plasma dispersion
effect for light phase modulation. Measurements of fiber-to-fiber losses, absorption coefficient, output intensity vs. time
and extinction ratio vs. frequency have been performed at λ=1.3 μm and at λ=1.55 μm. Results are reported and discussed in
this paper.
Received: 18 May 2001 / Revised version: 24 September2001 / Published online: 30 October 2001 相似文献
3.
H. Mendis A. Mitchell I. Belski M. Austin O.A. Peverini 《Applied physics. B, Lasers and optics》2001,73(5-6):489-493
The design and realisation of a SiO2 film-loaded Ti:LiNbO3 integrated acousto-optic tunable filter are presented. An optimised Hamming apodisation is achieved through introducing an
angular offset between the acoustic and optical waveguides along with carefully placed acoustic absorbers. The realised device
has a 20-mm acoustic interaction length and achieves a 3-dB linewidth of 1.8 nm with 19-dB sidelobe suppression. The realised
device is highly efficient, requiring a RF drive power of only 10 mW to achieve complete polarisation conversion. The enhanced
drive efficiency of the device is analysed using both acoustic and optical mode analysis. Based on this analysis, possible
explanations for the improved behaviour are presented and directions that may lead to further enhancements are discussed.
Received: 18 May 2001 / Revised version: 7 August 2001 / Published online: 23 October 2001 相似文献
4.
Realization of MMI Power Splitter by UV-light Imprinting Technique Using Hybrid Sol-Gel SiO2 Materials 下载免费PDF全文
An efficient fabrication scheme of buried ridge waveguide devices is demonstrated by UV-light imprinting technique using organic-inorganic hybrid sol-gel Zr-doped SiO2 materials. The refractive indices of a guiding layer and a cladding layer for the buried ridge waveguide structure are 1.537 and 1.492 measured at 1550nm, respectively. The tested results show more circular mode profiles due to existence of the cladding layer. A buried ridge single-mode waveguide operating at 1550 nm has a low propagation loss (0.088 dB/cm) and the 1× 2 MMI power splitter exhibits uniform outputs, with a very iow splitting loss of 0.029 dB at 1549nm. 相似文献
5.
Polarimetric investigation reveals up to ≈ 2 rad of reciprocal circular retardation present in 10 commercial X-cut, Z-propagation
LiNbO3 polarization transformers from two suppliers. A recent experiment confirms the static polarization mode coupling observed
in polarization transformers which are fabricated in-house using either off-axis or principal-axis propagation. Optical activity
is responsible for the nonideal behavior of the integrated electro-optic waveplates. This phenomenon is explained and accurately
modelled using LiNbO3 anisotropy. Furthermore the procedure required to make the polarization transformers ideal is given.
Received: 16 May 2001 / Revised version: 9 August 2001 / Published online: 23 October 2001 相似文献
6.
In this paper, we develop a model for the effects of waveguide sidewall roughness on the output uniformity and phase of a 3-dB MMI splitter. We achieve this by investigating analytically the effect of sidewall roughness on mode coupling in the MMI section of the splitter using the coupled mode and coupled power equations. Using these equations, the subsequent impact of mode coupling losses on the splitter output uniformity and phase is calculated and results for 1 × 2 and 2 × 2 splitters are presented and compared. Finally, to illustrate the impact of sidewall roughness on the operation of a waveguide device, the response of a Mach Zehnder interferometer comprising 2 × 2 splitters is investigated. 相似文献
7.
Two-phase and three-phase TE–TM mode converters for integrated optic polarization mode dispersion compensation are compared,
and the latter are found to have a slightly better electro-optic efficiency. If a small differential group delay is needed,
compensation performance can be drastically improved by a waveguide tilt in the YZ plane.
Received: 16 May 2001 / Published online: 23 October 2001 相似文献
8.
Self-imaging theory is widely accepted as a good method in designing 1 × N multimode interference (MMI) couplers, but it is also true that self-imaging theory is not suitable for low-contrast structures. An improved self-imaging theory is proposed in this paper for the optimal design of low-contrast 1 × N MMI couplers. The average effective width of MMI waveguide and the average effective propagation constant of MMI waveguide are used as the basis to modify the conventional self-imaging theory. A direct calculation of the average effective width of low-contrast MMIs is presented. We use this approach in the optimal design of a 1 × 4 silica MMI coupler, and the results show that the improved self-imaging theory is more accurate than conventional self-imaging theory for low-contrast structures, the results also show that if the material parameters and the width of an MMI waveguide are fixed, the average effective width of the MMI waveguide will increase with the decrease of the height of the core layer. 相似文献
9.
Vertically and laterally waveguide-coupled cylindrical microresonators in Si3N4 on SiO2 technology 总被引:1,自引:0,他引:1
D.J.W. Klunder E. Krioukov F.S. Tan T. van der Veen H.F. Bulthuis G. Sengo C. Otto H.J.W.M. Hoekstra A. Driessen 《Applied physics. B, Lasers and optics》2001,73(5-6):603-608
High-finesse laterally and vertically waveguide-coupled cylindrical microresonators have been designed and realized in Si3N4 on SiO2 technology using conventional optical lithography. Based on the experimental results and detailed simulations, a comparison
between the lateral and vertical coupling schemes is made.
Received: 16 May 2001 / Revised version: 13 August 2001 / Published online: 2 November 2001 相似文献
10.
S. Nolte M. Will J. Burghoff A. Tuennermann 《Applied Physics A: Materials Science & Processing》2003,77(1):109-111
Using tightly focussed femtosecond laser pulses, waveguides can be fabricated inside various glasses and crystals. This technique
has the potential to generate not only planar but three-dimensional photonic devices. In this paper we present, to the best
of our knowledge, the first true three-dimensional integrated optical device, a 1×3 splitter fabricated in pure fused silica.
The optical properties of this device and possibilities for the fabrication of complex high-density integrated optical elements
are discussed.
Received: 23 December 2002 / Accepted: 6 January 2003 / Published online: 28 March 2003
RID="*"
ID="*"Corresponding author. Fax: +49-3641/65-7680, E-mail: nolte@iap.uni-jena.de 相似文献
11.
J. Hübner S. Guldberg-Kjaer M. Dyngaard Y. Shen C.L. Thomsen S. Balslev C. Jensen D. Zauner T. Feuchter 《Applied physics. B, Lasers and optics》2001,73(5-6):435-438
New results in erbium-doped planar waveguide amplifiers and lasers are presented. The waveguides are produced in silica-on-silicon
technology using plasma-enhanced chemical vapor deposition. Waveguide propagation losses outside the erbium absorption band
are improved to values below 0.05 dB/cm for a core–cladding index step of around 1.4%. Amplifier arrays show a net gain of
more than 12 dB over the entire C-band.
Received: 13 June 2001 / Published online: 23 October 2001 相似文献
12.
相比于传统的1×N对称型多模干涉(Mult-Mode Interference,MMI)分束器设计,提出了一种新型埋入式弱限制光波导分束器件.它的干涉区及输入输出波导采用倒锥形式,器件尺寸减小,且不均匀性与附加损耗也减小.以1×4的对称型MMI分束器为例,当只对干涉区采用倒锥形结构后,在TE偏振中心波长为1.55 μm时,器件长度减小了500 μm,均匀性增加了0.131 dB,而附加损耗仅增加了0.02 dB,波长响应较传统设计增加了40 nm.在此基础上,又在输入输出臂上也各增加倒锥形结构后,相比于传统设计附加损耗减小了0.02 dB,均匀性增加了0.139 dB,器件长度减小了500 μm.改进后的器件具有优越的容差性.器件采用掺氟型聚合物材料进行优化设计,通过在合理范围内偏离输出波导位置,使输出光强达到最大值. 相似文献
13.
Xiang Wu 《Optics Communications》2006,258(2):135-143
A novel thermo-optic multimode interference (MMI) switch with a tapered heating electrode was proposed and the performance of the switch was simulated. An analytical steady-state heat-conduction model is also presented. In the design, one tapered heating electrode is used to alter the refractive index in the multimode slab region to realize the switching function. The simulation results indicate that the MMI switch can provide high extinction ratio, and good polarization- and wavelength-independence. The electric power consumption for the MMI switch is half of that of a switch with a straight heating electrode and similar to that of a Mach-Zehnder interferometer switch. 相似文献
14.
We report on a thin film InGaAsP laser integrated with a 1 x 4 polymer multimode interference (MMI) splitter on a silicon substrate for planar optical signal distribution. The thin film laser had a threshold current of 40 mA and was endfire coupled to the integrated passive polymer MMI splitter, and the optical signal from the laser was distributed to the four output waveguides of the MMI coupler. The measured loss of the MMI splitter was 0.79 dB. The normalized powers of the four MMI output ports in the integrated system were measured to be 0.823, 0.978, 0.852, and 1. 相似文献
15.
A 1310 and 1550 nm coarse wavelength multi/demultiplexer based on benzocyclobutene (BCB 4024-40) polymer is demonstrated for the first time. The device is designed based on a combination of general interference and paired interference mechanisms of multimode interference (MMI). It is fabricated on BK7 glass substrate with a thin layer of SiO2 as cover. A cost effective chemical etching technique is used in the fabrication process to take advantage of the photosensitive nature of the polymer. The device length was significantly reduced by adopting the restricted multimode interference scheme, lower beat length ratio and cascaded MMI couplers. The measured crosstalk at 1310 nm was 14.4 dB and at 1550 nm was 20.6 dB. The measured insertion loss is around 3.2-3.5 dB for both ports. 相似文献
16.
Some examples of interface studies are reported which show their close link with progress in III–V modern semiconductor device
physics and technology. The surface electronic properties investigated in-situ by reflectance anisotropy spectroscopy during
InGaP/InP growth (metal-organic vapor-phase epitaxy) are essential for the control of ordering phenomena in these layers,
which is relevant for high-performance optoelectronic devices. Studies of electronic interface states at metal/narrow-gap
III–V semiconductors are presented, which enabled the successful preparation of semiconductor/superconductor hybrid devices.
For group-III nitrides with wurtzite structure the presence of fixed polarization interface charges yields new challenges
in order to understand and control Schottky-barrier heights, band offsets and 2D confinement in heterostructure field-effect
transistors.
Received: 26 April 2001 / Accepted: 23 July 2001 / Published online: 3 April 2002 相似文献
17.
一种新型SOI Mach-Zehnder干涉型电光调制器的设计 总被引:8,自引:8,他引:0
在超紧缩双曲锥形3dB多模干涉耦合器的基础上,设计了一种新的Silicon-on-insulator (SOI) Mach-Zehnder干涉型电光调制器.与传统的Y分支器相比,双曲锥形3dB耦合器的制作容差大,而长度缩短了近30%,使得整个器件的尺寸大幅减小.调制区采用横向注入的PIN结构,模拟结果表明:当外加偏压为0.86V时,器件的调制深度最大,此时注入电流为13.2mA,对应的器件功耗为11.4mW. 相似文献
18.
Passband broadening of an AWG (array waveguide grating) demultiplexer with an MMI (multimode interference) coupler connected at the end of a tapered input waveguide is considered. An explicit formula based on the field propagation of an approximate Hermit-Gaussian beam is used to calculate quickly and reliably the spectral response of the AWG demultiplexer. The widths of the input waveguide, the output waveguides and the MMI coupler are optimized. The optimal design is verified with the experimental measurement. 相似文献
19.
20.
Tunable and switchable all-fiber comb filter using a PBS-based two-stage cascaded Mach-Zehnder interferometer 总被引:1,自引:0,他引:1
We propose and demonstrate a novel tunable and switchable all-fiber comb filter by employing a polarization beam splitter (PBS)-based two-stage cascaded Mach-Zehnder (M-Z) interferometer. The proposed comb filter consists of a rotatable polarizer, a fiber PBS, a non-3-dB coupler and a 3-dB coupler. By simply adjusting the polarization state of the input light, the dual-function of channel spacing tunable and wavelength switchable (interleaving) operations can be efficiently obtained. The theoretical analysis is verified by the experimental results. A comb filter with both the channel spacing tunable from 0.18 nm to 0.36 nm and the wavelength switchable functions is experimentally demonstrated. 相似文献