An efficient structure to excite the fundamental mode in single-mode slab waveguides is proposed. The configuration consists of a tapered waveguide with nonlinear cladding. The numerical results show that the configur...
详细信息
An efficient structure to excite the fundamental mode in single-mode slab waveguides is proposed. The configuration consists of a tapered waveguide with nonlinear cladding. The numerical results show that the configuration is less sensitive to the offset between coupled waveguides and an excitation efficiency of 92% or more can be obtained.
Results on S-bend losses in fibre-compatible K+-Na+ ion-exchanged waveguides are presented. For the first time a distinction has been made between pure bend loss and transition loss. Experimental results are compared ...
详细信息
Results on S-bend losses in fibre-compatible K+-Na+ ion-exchanged waveguides are presented. For the first time a distinction has been made between pure bend loss and transition loss. Experimental results are compared to those of two theoretical models. Lateral offsets in waveguide junctions to reduce transition loss are investigated. This set of results can be used to optimise the design of S-bends with respect to length and loss.
Hollow sapphire waveguides have been successfully employed for remote radiometric temperature measurements over an extended temperature range (30-degrees-C to 1650-degrees-C). These waveguides not only exhibit an infr...
详细信息
Hollow sapphire waveguides have been successfully employed for remote radiometric temperature measurements over an extended temperature range (30-degrees-C to 1650-degrees-C). These waveguides not only exhibit an infrared transmission window from 10 to 17-mu-m, which permits low temperature blackbody detection, but the sapphire also possesses an intrinsic melting point of 2053-degrees-C, enabling their operation in high temperature environments.
In this paper the power coupling expression between two identical axially aligned and spatially separated waveguides is presented. Calculations using the coupling expression for a Gaussian mode profile in the input wa...
详细信息
In this paper the power coupling expression between two identical axially aligned and spatially separated waveguides is presented. Calculations using the coupling expression for a Gaussian mode profile in the input waveguide produce results that are in excellent agreement with experimental observations.
Fabrication and characterisation of Er:Ti:LiNbO3 channel waveguides is reported. A lifetime of 2.4 +/- 0.2 ms has been measured for the 4I13/2 level. In a pump and probe experiment using a high power InGaAsP laser and...
详细信息
Fabrication and characterisation of Er:Ti:LiNbO3 channel waveguides is reported. A lifetime of 2.4 +/- 0.2 ms has been measured for the 4I13/2 level. In a pump and probe experiment using a high power InGaAsP laser and a tunable DBR laser, a signal increase of 0.75 dB for a transmitted pump power of 4.8 mW was demonstrated.
The use of integrated waveguides with a limited interaction region in contact with a sensitive medium presents great potentialities for the development of optical sensors. In this paper, we describe a new fabrication ...
详细信息
The use of integrated waveguides with a limited interaction region in contact with a sensitive medium presents great potentialities for the development of optical sensors. In this paper, we describe a new fabrication process of ion-exchange waveguides well suited for integrated sensor applications. The principle of fabrication is as follows. During the first step, a channel waveguide is generated at the surface of a glass substrate by thermal ion-exchange. Then a rectangular pattern mask is transferred onto the central portion of the waveguide by standard photolithographic techniques. During the second step, the wafer is immersed in a molten salt and an external electric field is applied across the glass substrate. As the aluminium mask acts as a blocking barrier, only the unmasked regions of the waveguide are buried whereas its central region remains located close to the surface. For a single-mode waveguide at 780 nm, we measured propagation losses of 0.13 dB/cm for the buried portion, 2.80 dB/cm for the surface portion and losses of 0.40 dB for the transition region. For this structure, we also observed a deformation of the fundamental mode. The proposed method is easy to implement and permits the topography of the elaborated waveguides to be controlled precisely.
GaInAs/InP pin photodetectors K+ -exchanged channel glass waveguides have been integrated using substrate etch-off, a variation of epitaxial lift-off. Coupling of 1.3-mu-m wavelength light from the single mode glass w...
详细信息
GaInAs/InP pin photodetectors K+ -exchanged channel glass waveguides have been integrated using substrate etch-off, a variation of epitaxial lift-off. Coupling of 1.3-mu-m wavelength light from the single mode glass waveguide to the photodetectors is characterised and is found to be in good agreement with calculated values.
The relative scattering losses due to rough rib sidewalls in single and double heterostructure rib waveguides are investigated theoretically. We find that double heterostructures exhibit at least as much scattering lo...
详细信息
The relative scattering losses due to rough rib sidewalls in single and double heterostructure rib waveguides are investigated theoretically. We find that double heterostructures exhibit at least as much scattering loss as single heterostructures, provided that such comparisons are made among structures with comparable bend performance.
An easy to use and extremely fast computational technique is presented for estimating the minimum usable radius of deeply etched, curved rib waveguides. This method is based on the effective index method and estimates...
详细信息
An easy to use and extremely fast computational technique is presented for estimating the minimum usable radius of deeply etched, curved rib waveguides. This method is based on the effective index method and estimates the radius of curvature at which the bend becomes cut off due to substrate leakage.
The realisation of singlemode rib waveguides in silicon-on-insulator (SOI) having a width and height of several micrometres is reported. Measurements at a wavelength of 1.3 and 1.55-mu-m yield waveguide losses below 0...
详细信息
The realisation of singlemode rib waveguides in silicon-on-insulator (SOI) having a width and height of several micrometres is reported. Measurements at a wavelength of 1.3 and 1.55-mu-m yield waveguide losses below 0.5 dB/cm and an excellent agreement of the near field intensity distribution with the one predicted by a BPM simulation.
暂无评论