Abstract: The invention provides an optical measurement system and method for monitoring the condition of a sail, the system comprising: an optical interrogation unit that produces and receives an optical signal; and an optical fibre network that interconnects the interrogation unit with a plurality of optical sensors in communication with the sail, wherein the sensors are mounted onto the sail. The optical system measures parameters of the sail, from which shape, integrity and overall conditions of the sail can be calculated in real-time.

Abstract: A method relating to the calibration of tuneable lasers is described. The method provides for the provision of correct control currents so as to achieve each of desired output frequencies from the laser. The correct currents are determined by forming a matrix of the output characteristics of the laser at specific tuning currents and processing that matrix to determine stable operating points within the matrix.

Abstract: The invention provides a method and system for compensating variations in tuning efficiency and power of a multi-section tunable laser diode. The invention comprises a means to obtain a set of values for a specific section of the laser diode and a means to normalise the values to compensate the non-linearities in the set of values, hence compensating for variations in the tuning efficiency for that particular section of the laser diode. The invention is advantageous in that it is generic and can be applied to several different types of lasers. A further advantage of the invention is that the mode width can be determined as well as the mode modulation of the tunable laser.