This paper reports the development of an infra-red circa 193THz (~1.5μm) frequency tunable laser source
selected and evaluated for photonic environment sensing systems. LIDAR (LIght Detection And Ranging)
offers a method of remote wind speed measurement. Widespread deployment of the technique has been limited
by the expense and complexity of LIDAR systems. However development of systems based on optical fiber and
photonic components from the telecommunications industry promises improvements in cost, compactness, and
reliability, so that it becomes viable to consider deployment of such systems on large wind turbines for the
advance detection of fluctuations of wind speed. A monolithic multi-section laser, originally designed as a
tunable source for telecommunications applications, has been modified and re-evaluated as a source for sensing
applications, based on the technique of coherent laser radar (CLR), and coherent doppler LIDAR (CDL). A
tunable frequency optical source should fulfil specific technical criteria to fulfil the applications requirements;
speed of frequency selection, absolute accuracy of emitted frequency, spectral purity, and stability. Custom
electronics and firmware were developed to realise an improvement in frequency switching speed by a factor of
10 relative to equivalent commercially available telecoms (DBR) sources, satisfying the target application
requirements. An overview of the sensing architecture is presented, a detailed description of the fast tuning
process described, including the custom hardware and firmware, and specifically the laser energising sequence.
The results of the laser module are then presented with detailed consideration of the target application.
This paper describes a MEMS (micro-electromechanical systems) modulator suitable for optical system network
signaling. Several actuator mechanisms exist that potentially satisfied this purpose, electrostatic actuation was identified
as the most suitable for the application due to speed of operation and low power consumption. MEMS geometry and
analytical mode models were developed and applications performance estimated including multiphysics phenomena.
Finite element analysis was undertaken using the commercially available software suite, COMSOL<sup>(R)</sup>, performing static
and dynamic simulations and analyses in the time and frequency domains. The proposal is that the MEMS modulator
would be integrated with other optical components encased in a hermetically sealed vacuum environment, resulting in a
lightly damped response with decaying oscillation. A two-step drive signal was developed and simulated using the multidomain,
simulation package SIMULINK®. The optimized MEMS design and two-step driver realized a MEMS optical
modulator meeting the required specification. Finally a proposal for integration within an optical transmitter assembly is
The Tuneable Transmitter Assembly is a high performance tuneable transmitter for use in the C or L wavelength bands of and suited to regional metro and long-haul applications. The key performance attributes of the TTA module is successfully demonstrated in this paper.