Sumiaty Ambran

In situ loss measurement of direct UV-written waveguides using integrated Bragg gratings

The propagation loss of a direct UV-written silica-on-silicon waveguide is measured using an elegant nondestructive method. The technique uses integrated Bragg grating structures, which are observed from opposing launch directions to obtain information about the optical power at different positions along the length of the waveguide. Critically, the technique is ratiometric and independent of coupling loss and grating variability. This high-precision measurement is suitable for low-loss planar waveguides. From this data, the propagation loss of the UV-written waveguides was observed to be 0.235+/-0.006 dB/cm.

Fabrication of a Multimode Interference Device in a Low-Loss Flat-Fiber Platform Using Physical Micromachining Technique

A physical micromachining technique is demonstrated in a low-loss flat-fiber substrate to fabricate a multimode interference (MMI) device. The flat-fiber substrate is a low-index-contrast material; however, by making use of two physically micromachined trenches, lateral confinement is achieved providing high index contrast for the MMI region. A 1 × 3 MMI device exhibiting 1.89 dB of excess loss has been demonstrated.

Micromachined multimode interference device in flat-fiber

We demonstrate a new approach for fabricating multimode interference (MMI) devices using micromachining of a novel flat-fiber platform. A 1×3 splitter has been demonstrated together with spatial output mode control by index tuning of material within micromachined trenches.

UV Written Planar Bragg Grating Sensors - An Overview of Fabrication, Geometries and Applications

The presentation will give an overview of the fabrication process of direct UV written planar Bragg grating sensors and the various geometries and applications investigated over the last several years.

Doppler velocity measurement with self-mixing effect of direct modulated laser diode enabling velocity direction

Doppler Laser Velocity measurement by self-mixing effect using direct modulation laser diode is proposed to distinguish the direction of the object movement. To distinguish the movement direction in conventional way, it is needed to assemble a frequency shift device such as an acoustic optic cell in the optical system. However, the self-mixing scheme cannot satisfy this condition this due to its simple system. Therefore, we applied triangularwave modulation current with repetition frequency of 250Hz directly to the laser diode emitting at a wavelength of 780nm. Target speed of 0.1 - 0.4 cm/s is measured and its movement direction forward and/or backward can be distinguished successfully. Both the velocity and moving direction of the target are obtained.

Optical coupling devices fabricated using UV-curable resin for board level optical interconnect

It is expected that opto-electronic printed wiring board (OE-PWB) will appear very soon. We study optical coupling schemes to multi-layer and multi-channel OE-OWB, and propose several optical coupling devices fabricated by using UV-curable resin. The “optical pin” is a vertical optical pillar, and that is one promising approach to achieve optical coupling with 90-deg path conversion between surface devices and optical wiring. Analysis using Optical Ray Tracing method shows that optical pin has potential to achieve higher optical coupling efficiency and larger positional tolerance. The optical pin can be fabricated by the Mask-Transfer Self-Written Waveguide (SWW) method using UV-curable resin. Next we propose optical coupling device with micro lens array. The advantage of using micro lens is that there will be no interaction between the beams crossings which means no crosstalk and noise will not occur. In addition, micro lens is flexible for fabrication. Starting fabrication of a single micro lens on tip of fiber, we succeeded in fabrication of micro lens array on patterned substrate.

Refractive Index Sensing in an Optically Integrated Flat-fiber Substrate

An optical flat-fiber substrate is presented for refractive index sensor. A series of Bragg grating is used as a sensing tool. A maximum sensitivity to approximately 95 nm per refractive index unit has been achieved.

UV-written Bragg gratings in a flat-fiber platform as a bending and twisting sensor

High demand on structural health monitoring has encouraged the development of smart structure geometries to be more effective and competitive [1]. One of the technologies that has been integrated into these structures is the fiber Bragg grating (FBG) [2]. The FBG is a mature technology that has seen many applications, particularly the field of sensing where it has many advantages such as immunity to electromagnetic field, long lifetime, high sensitivity, lightweight and low loss. There are several types of optically based physical sensors. Most of which are fabricated in a standard dimension silica optical fiber which due to its cylindrical structure are unable to independently measure twist. Here we demonstrate a bending and twist sensor fabricated in a flat-fiber substrate. A Y-splitter and a series of Bragg gratings along the 50 mm length provides a differential signal providing distinction between bend and twist within the sample.