共查询到20条相似文献,搜索用时 46 毫秒
1.
《Lightwave Technology, Journal of》1995,13(10):2069-2074
A 1-by-64 multimode interference power splitter in SiO2 has been designed for use in fiber-optics communication systems. The splitter exhibits a minimum loss of 0.5 db and a uniformity of 1.7 dB at a wavelength of 1.55 μm. The polarization sensitivity is below 0.14 dB, the reflection level below -55 dB, and the optical bandwidth 30 nm. The fabrication tolerances are ±0.1 mm on the length and ±3.5 μm on the width of the multimode section of the splitter. In comparison with a branching-type splitter it is found that the designed device is approximately 30% shorter than the branching-type device for comparable losses 相似文献
2.
A novel polarization-beam splitter/switch with a Mach-Zehnder interferometer configuration was fabricated using a silica-based planar lightwave circuit (PLC) on a silicon substrate. The polarization-beam splitter/switch was realized by accurately controlling the waveguide birefringence and the phase state by laser trimming two kinds of stress-applying amorphous silicon film with widths of 50 μm and 95 μm. Fiber-waveguide-fiber insertion loss of 0.5 dB and crosstalk attenuations of over 25.6 dB were attained 相似文献
3.
A waveguide polarizer using an ARROW (antiresonant reflecting optical waveguide) structure, of which the first cladding consists of three thin layers, is proposed. Theoretical calculation shows that this polarizer can achieve isolation over 30 dB/cm with an insertion loss of 0.01 dB/cm at 1.3 μm. Isolation of 83 dB/cm with insertion loss of 4.3 dB/cm was experimentally obtained at 0.633 μm. This structure is suitable for the integration of a polarization splitter and photodetector 相似文献
4.
Efficient 1*16 optical power splitter based on InP 总被引:1,自引:0,他引:1
An InP-based 1*16 optical power splitter is demonstrated. The device has 250 mu m spaced output channels and a total length of 5.1 mm. This small size was realised by using a free-space radiative input-output coupling and specially designed 1.85 mm curvature S-bends. The worst case excess loss for TM and TE polarised light is 3 dB.<> 相似文献
5.
Novel beam splitters with optimized waveguide structures are designed and fabricated using reactive ion etching. At 1.15 μm the excess loss of the beam splitter is measured to be 1.2 dB for TE and 1.8 dB for TM polarizations, respectively 相似文献
6.
Suning Tang Chen R.T. Garrett L. Gerold D. Li M.M. 《Lightwave Technology, Journal of》1994,12(11):1971-1975
We utilize a novel diffraction formalism to study the crosstalk effect in a highly parallel free-space optical interconnect based on two-dimensional arrays of surface-emitting laser diodes, microlenses, and photodetectors. The diffraction induced crosstalk between adjacent laser diodes in each detector to the system limitations is investigated. Optimum design rules and formulas are given for the first time, to include the relation of channel packaging density and interconnect length to the design parameters of the optical interconnect components. The design formulas developed here yield an optimum detector size and indicate a tradeoff between channel packaging density and interconnect length. The feasibility of such a free-space interconnect with a channel packaging density of 3460 channels/cm2 and 2.0 cm interconnection length is determined using typical parameters of detector radius from ~5 to ~45 μm, lens radius of 85 μm, and laser diode radius of ~5 pm operating at wavelength 0.67 pm for signal-to-noise ratio above 17 dB. Some experiments were conducted to measure the diffraction induced crosstalk and optical link efficiency 相似文献
7.
Ruey-Ching Twu Chia-Chih Huang Way-Seen Wang 《Electronics letters》2000,36(3):220-221
A coupling type mode splitter with an extraordinary polarisation and a random polarisation waveguide made by Ni and Ti indiffusion, respectively, on a Z-cut LiNbO3 substrate is described for the first time. With optimised process parameters: a very small TM mode profile mismatch is obtained due to the similar characteristics of the Ti- and Ni-diffused waveguides. The measured extinction ratios of the TE and TM modes at 1.55 μm wavelength are >22 dB 相似文献
8.
Waveguide polarization-independent optical circulator 总被引:1,自引:0,他引:1
Sugimoto N. Shintaku T. Tate A. Terui H. Shimokozono M. Kubota E. Ishii M. Inoue Y. 《Photonics Technology Letters, IEEE》1999,11(3):355-357
We fabricated a new type of waveguide polarization-independent optical circulator which does not need a polarization-beam splitter. The circulator is based on a non-reciprocal Mach-Zehnder interferometer which consists of two waveguide Faraday rotators, two thin-film half-waveplates and two planar lightwave circuit-type 3-dB couplers. The fabricated circulator provides a 14.0-23.7-dB isolation and a 3.0-3.3 dB insertion loss at λ=1.55 μm. This circulator presents a new possibility for developing non-reciprocal devices in the field of integrated optics 相似文献
9.
Optical crossconnects with large port counts are fast becoming critical components for high-capacity optical transport networks. The free-space micromachined optical switches (FS-MOS) demonstrated in this letter represent a means of filling this network need by combining the advantages of free-space interconnection with the virtues of integrated optics. Featuring free-rotating hinged micromirrors, the switch overcomes the common drawback of mechanical-type switches, namely long switching time. Measurements have revealed switching times less than 700 μs, crosstalk less than -60 dB, extinction ratio greater than 60 dB, negligible polarization-dependent loss, and excellent bit-error-rate (BER) performance 相似文献
10.
Kuen-Cherng Lin Wei-Ching Chuang Wei-Yu Lee 《Lightwave Technology, Journal of》1996,14(11):2547-2553
We propose a novel, high-performance directional-coupler polarization splitter using a nematic liquid crystal (NLC) as the coupling layer. The beam propagation method is used to investigate the propagation characteristics of the device under various conditions. Results of numerical calculations relevant to the design conditions are presented. Because of the large birefringence of NLC, a very short device length of 140 μm is achievable at a high extinction ratio of 28 dB 相似文献
11.
Suzuki Y. Iwamura H. Miyazawa T. Mikami O. 《Quantum Electronics, IEEE Journal of》1994,30(8):1794-1800
The operating principle of our polarization mode splitter is based on the polarization-dependent refractive index changes induced by disordering InGaAs/InP superlattices. We disordered superlattices by the Si3N4 cap-annealing method and measured the near-field patterns to confirm that the device functioned properly at a wavelength of 1.52 μm. The crosstalk was about -10 dB. We should be able to improve the characteristics of this device by optimizing its structure. This device requires no electrical control and will be very suitable for semiconductor monolithic integrated circuits 相似文献
12.
A glass waveguide polarization splitter for operation in the 1.3 μm wavelength region is reported. The device, which has a symmetric directional coupler configuration, exploits the stress-induced birefringence in K+-Na+, ion-exchanged waveguides, giving rise to an adequate difference in the coupling lengths for the two polarizations. Starting from the measured potassium concentration (refractive index) profile of the structure and utilizing a combination of the multilayer stack theory and the effective-index method, the normal mode propagation constants and mode field profiles are calculated to determine the polarization splitting length and the extinction ratio, and the results are compared with the experimental data. It is shown that in a given coupler, the splitting occurs at several wavelengths in the 1.0-1.45 μm range. A 25 mm-long coupler, fabricated by thermal diffusion of K+ ions in BK7 glass, exhibits an extinction ratio of 18.2 dB at 1.32 μm, in excellent agreement with the simulation results 相似文献
13.
Propagation loss and delay spread were studied experimentally, in order to design digital mobile communication systems. For propagation loss, the results were as follows, (i) When there are no obstacles on the road, the distance over which a radio wave propagates with only free-space loss increases with frequency. (ii) When there are obstacles (trucks and buses). and when the base station antenna heights are 5 and 15 m. the loss in excess of the free-space loss is 15 and 10 dB, respectively, at 1 km, (iii) Frequency dependence of this excess loss is not significant. (iv) On a cross road. the loss increases rapidly traveling away from the intersection. For the delay spread. the results were as follows. (i) The delay spread increases slightly with distance (less than 0.3 μs within 1 km). (ii) The standard deviation of the delay spread increases slightly with distance (less than 0.2 μs). Using the above results. a service area that extends along the road on which the base station is located and is limited in distance along cross roads can be predicted 相似文献
14.
Martini R. Bethea C. Capasso F. Gmachl C. Paiella R. Whittaker E.A. Hwang H.Y. Sivco D.L. Baillargeon J.N. Cho A.Y. 《Electronics letters》2002,38(4):181-183
Experimental results for an optical free-space high-speed link using direct modulated mid-infrared (λ = 8.1 μm) quantum cascade lasers are presented. A total of 800 digitally encoded multimedia channels were transmitted. The reliability of the system against weather influence (fog) was experimentally compared to that of a near-infrared (λ = 0.85 μm) link 相似文献
15.
Variable bandwidth filters have been fabricated using silica-based N×N arrayed-waveguide gratings. The centre wavelengths are λ0=1.55 μm for all channels. The 3 dB bandwidths are 40, 78, 116 and 154 GHz, for the filter with a path length difference ΔL=63 μm. In the filter with ΔL=8.6 μm, the 3 dB bandwidths are 414, 769, 1198 and 1608 GHz. The on-chip losses are 2.1-2.9 dB and sidemode suppression ratios are larger than 27 dB 相似文献
16.
Biedenbender M.D. Kapoor V.J. Shalkhauser K.A. Messick L.J. Nguyen R. Schmitz D. Jurgensen H. 《Microwave Theory and Techniques》1991,39(8):1368-1375
The microwave characteristics at 18 and 20 GHz of submicron-gate indium phosphide (InP) metal-insulator-semiconductor field-effect transistors (MISFETs) for high output power density applications are presented. InP power MISFETs were fabricated with 0.7 μm gate lengths, 0.2 mm gate widths, and drain-source spacings of 2, 3 and 5 μm. The output power density was investigated as a function of drain-source spacing. The best output power density and gain were obtained for drain-source spacings of 3 μm. At 18 GHz output power densities of 1.59 W/mm with a gain of 3.47 dB and a power-added efficiency of 20.0% were obtained for a drain-source spacing of 3 μm. At 20 GHz output power densities of 1.20 W/mm with a gain of 3.17 dB and a power-added efficiency of 13.6% were obtained for a drain-source spacing of 3 μm 相似文献
17.
We have proposed and demonstrated a polarization splitter based on an ARROW-B type waveguide. This device has an asymmetric Y-branch configuration, connecting a waveguide with a large modal birefringence to a low-birefringent waveguide which is channeled by a stripe lateral confinement structure. The device can achieve a high extinction ratio without precise mask alignment, since these two waveguides are connected by a self-alignment process. In addition, a low insertion loss is achieved because of adiabatic Y-branching. We designed this device at the wavelength of 1.55 μm and fabricated it using RF sputtering. As a result, high extinction ratios of -19.4 dB for TE mode and -19.0 dB for TM mode were achieved 相似文献
18.
Ghirardi F. Mersali B. Brandon J. Herve-Gruyer G. Carenco A. 《Photonics Technology Letters, IEEE》1994,6(4):522-524
A spot-size transformer structure is proposed for InP/InGaAsP double-heterostructure (DH) rib waveguide. Vertical expansion of a factor of 7 is achieved with 3 dB internal loss. Coupling from standard cleaved fibre (11 μm diameter mode) to a DH rib waveguide (5.8×0.8 μm large mode), is achieved with 4.5 dB polarisation independent loss. Coupling tolerances are highly relaxed. The fabrication method uses a thin cladding layer which ends up to a quasi-planar structure suitable with further integration process 相似文献
19.
Byung-Tak Lee Min-Suk Kwon Jun-Bo Yoon Sang-Yung Shin 《Photonics Technology Letters, IEEE》2000,12(1):62-64
Polymeric large-core (47 μm×41 μm) optical waveguides for optical interconnects have been fabricated by using a rubber molding process. For low-cost low-loss large-core waveguides, our newly developed thick-photoresist patterning process is used for a master fabrication. Also a low-loss thermocurable polymer, perfluorocyclobutane (PFCB), is used in fabricating optical waveguides by rubber molding for the first time. The propagation loss is measured to be 0.4 dB/cm at the wavelength of 1.3 μm, and 0.7 dB/cm at the wavelength of 1.55 μm 相似文献
20.
Adar R. Henry C.H. Kazarinov R.F. Kistler R.C. Weber G.R. 《Lightwave Technology, Journal of》1992,10(1):46-50
The performance of adiabatic 3-dB couplers and V -branches is reported. These devices are broadband and divide power equally. They have no observable polarization dependence. Typical excess losses relative to a straight waveguide is 0.1-0.2 dB for the 3-dB couplers and about 0.4 dB for the V -branches. Fiber to fiber insertion loss of 0.31 dB was measured for a 2.5-cm straight waveguide. The devices were used to fabricate transmission filters peaked at 1.55 μm and power combiners having two channels at 1.48 and 1.55 μm. The device fabrication was improved by use of a flowable top cladding layer containing boron and phosphorous which easily filled-in between closely spaced waveguides 相似文献