Design and fabrication of photonic devices based on multimode interference
The actual tendency on microfabrication of device structures based on optical fibers have yield to multiple interesting applications. This because them rapid response and great capacity for data transmission. Such devices are developed by using either a combination of single mode and multi-mode fibe...
| Autor: | |
|---|---|
| Tipo de recurso: | tesis doctoral |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2012 |
| País: | México |
| Institución: | Instituto Nacional de Astrofísica, Óptica y Electrónica |
| Repositorio: | Repositorio Institucional del INAOE |
| Idioma: | inglés |
| OAI Identifier: | oai:inaoe.repositorioinstitucional.mx:1009/736 |
| Acceso en línea: | http://inaoe.repositorioinstitucional.mx/jspui/handle/1009/736 |
| Access Level: | acceso abierto |
| Palabra clave: | info:eu-repo/classification/Ajuste de láser/Laser tuning info:eu-repo/classification/Láser de fibra/Fiber lasers info:eu-repo/classification/Sensores de fibra óptica/Fibre optic sensors info:eu-repo/classification/Interferencia multimodo/Multimode interference info:eu-repo/classification/cti/1 info:eu-repo/classification/cti/22 info:eu-repo/classification/cti/2209 |
| Sumario: | The actual tendency on microfabrication of device structures based on optical fibers have yield to multiple interesting applications. This because them rapid response and great capacity for data transmission. Such devices are developed by using either a combination of single mode and multi-mode fibers or by using them separately. On many occasions, it is necessary to introduce some other materials in order to improve their performances and to provide responses not accessible using just fibers. That is the case of the devices presented in this Thesis, which are based on the multimode interference effect arising in MMFs. In the present work we have developed the following devices: We present the design and implementation of a micro-displacement sensor. The structure is composed by a piece of MMF spliced to another segment of SMF. Then, another SMF is inserted into a capillary tube filled with index matching liquid. Since the refractive index of the liquid is higher than the one of the tube, a liquid multimode guide (diameter of 125 μm) is induced between the inner fibers. As a result, when the fibers are separated this effectively increases the length of the MMF. Since the peak wavelength response of MMI devices is very sensitive when the MMF length is modified. Two liquid level sensors were developed using two different MMF: a standard 105/125 and a special MMF. The 105/125 MMF provides discrete operation, while the special MMF provides both continuous and discrete liquid level sensing. In both cases multiplexing is achieved by using different MMF lengths in the MMI device, and the refractive index of the liquid can be also measured. The use of the special fiber has the advantage that its sensing range can be increased during continuous level sensing by using a longer MMF which correspond to higher self-imaging orders. A temperature sensor consisting of a MMF without cladding surrounded by index matching liquid was showed. Since the liquid used has a higher thermooptic coefficient than silica, when the sensor is heated the MMI spectral response is significantly modified. We show also that by reducing the core diameter of the MMF the sensitivity is further enhanced. An optofluidically tunable bandpass filter for fiber laser applications is demonstrated. |
|---|