Estimation of the fibre temperature during the inscription of arc-induced long-period gratings

Abstract

The underlying formation mechanisms and the properties of long-period gratings produced through arc discharges are intrinsically related to the temperature reached by the fibre during arc exposure. In this work, the determination of the fibre temperature was based on PlankÕs blackbody radiation law. The radiation emitted by the optical fibre during heating due to an electric arc discharge, detected using a Cronin spectrometer, was fitted to the emission spectrum of the blackbody radiation, allowing the estimation of the temperature range attained by the fibre. A peak temperature of 1400 ± 50°C was obtained.

Estimation of the fiber temperature during an arc‐discharge

“…The respective peak temperatures calculated for the fiber (capillary) was of about 1350°C (1445°C). The fiber temperature values agree well with those obtained using other techniques [5]. This method allows the measurement of an important parameter, the fiber temperature under electrical arc discharges that concerns not only the control of the LPGs fabrication process, but also the mechanisms responsible for their formation.…”

“…The correspondent capillary peak temperature is of about 1445°C, in good agreement with the value obtained from Figure 5. The peak value of the fiber temperature of ϳ1350°C is also in good agreement with the value obtained through the blackbody radiation method [5].…”

“…In this context, the determination of the temperature reached by the fiber during the electric arc discharge is an essential parameter for the correct assessment of the influence of each potential mechanism. Recently, based on blackbody radiation, we estimated a value of (1400 Ϯ 50)°C for the fiber temperature [5]. In a previous work carried out using electrically insulated thermocouples [6], a value of ϳ1320°C was obtained for the temperature attained by an optical fiber during an arc discharge.…”

“…Except the measurement applications, the microstrip ring resonator has also been used in filters, oscillators, mixers, and antennas [5] because of its advantages of compact size, easy fabrication, narrow passband bandwidth, and low radiation loss. The interesting compact filters such as dualmode filters using microstrip ring resonators for cellular and other mobile communication systems have been reported [6].…”

“…However, the dualmode ring or patch BPFs usually has narrow bandwidth due to their natural properties [1][2][3]. In 2003, Chang et al first proposed a design of a planar dual-mode wideband BPF [4,5], which used a ring resonator without the perturbation element and with directconnected orthogonal feed lines and two tuning stubs to construct a wide passband with 3-dB fractional bandwidth ratio (FBW, defined as 3-dB bandwidth over designed center frequency) of 49.3%. However, the filter had serious spurious responses below or above the passband due to its direct-connected feed lines.…”