Stable multiwavelength semiconductor optical amplifier-based fiber laser using a 2-mode interferometer

A multiwavelength semiconductor optical amplifier (SOA) fiber laser based on all-fiber two-mode interferometer (TMI) structure is demonstrated. The TMI generates in a comb-like spectrum with a 1-nm wavelength spacing and extinction ratio of 5.7 dB. By incorporating a TMI in the laser cavity, stable multiwavelength operation is obtained with 30 output channels from 1570.8 to 1600.8 nm with peak powers of at least 10 dB from the highest peak. The output comb spectrum and the overall stability of the multiwavelength are also enhanced with by inducing the four-wave-mixing effect in the cavity. The multiwavelength SOA fiber laser shows high operational stability with peak power fluctuations exceeding 1 dB observed only at the 1st, 23rd, 26th, and 30th peaks, which are at the ends of the multiwavelength spectrum

Graphene-PVA saturable absorber for generation of a wavelength-tunable passively Q-switched thulium-doped fiber laser in 2.0 μm

Graphene, a 2D material, has been used for generation of pulse lasers due to the presence of its various fascinating optical properties compared to other materials. Hence in this paper, we report the first demonstration of a thulium doped fiber laser with a wavelength-tunable, passive Q-switched output using a graphene-polyvinyl-alcohol composite film for operation in the 2.0 µm region. The proposed laser has a wavelength-tunable output spanning from 1932.0 nm to 1946.0 nm, giving a total tuning range of 14.0 nm. The generated pulse has a maximum repetition rate and average output power of 36.29 kHz and 0.394 mW at the maximum pump power of 130.87 mW, as well as a pulse width of 6.8 µs at this pump power. The generated pulses have a stable output, having a signal-to-noise ratio of 31.75 dB, and the laser output is stable when tested over a period of 60 min. The proposed laser would have multiple applications for operation near the 2.0 micron region, especially for bio-medical applications and range-finding

1.3 μm dissipative soliton resonance generation in Bismuth doped fiber laser

In this work, a Figure-9 (F9) bismuth-doped fiber laser (BiDFL) operating in the dissipative soliton resonance (DSR) regime is presented. The 1338 nm laser used a BiDF as the active gain medium, while a nonlinear amplifying loop mirror (NALM) in an F9 configuration was employed to obtain high energy mode-locked pulses. The wave breaking-free rectangular pulse widened significantly in the time domain with the increase of the pump power while maintaining an almost constant peak power of 0.6 W. At the maximum pump power, the mode-locked laser delivered a rectangular-shaped pulse with a duration of 48 ns, repetition rate of 362 kHz and a radio-frequency signal-to-noise ratio of more than 60 dB. The maximum output power was recorded at around 11 mW with a corresponding pulse energy of 30 nJ. This is, to the best of the author’s knowledge, the highest mode-locked pulse energy obtained at 1.3 μm as well as the demonstration of an NALM BiDFL in a F9 configuratio

A Victor's History: A Comparative Analysis of the Labour Historiography of Indonesia's New Order

Some observers have identified a common pattern in developing countries whereby unions are transformed from a political force valued for their contribution to the struggle for independence to a state-sponsored ‘tool of development’. A less well-explored question concerns the harnessing of labour historiography to justify such transitions. As this article shows, Suharto’s New Order (1966–98) undertook a conscious and purposeful rewriting of Indonesian labour history in support of a single vehicle of labour representation organized around a narrative of the dangers of political unionism and designed to control and harness the industrial workforce in the name of economic development

Seni dan Sastra

Rakyat Indonesia tidak hanya kreatif dalam menerima warisan nenek moyang, tetapi juga dalam menerima yang datang dari luar. Keroncong yang sekarang sudah menjadi milik Rakyat Indonesia di seluruh Nusantara merupakan contoh. kreativitas dalam menerima yang datang dari luar. Pun wayang, gambus, terbangan (rebana) dan arsitektur tidak diterima "sebagaimana adanya" saja. Demikian pula bentuk-bentuk kesenian lainnya, baik yang datang dari Barat maupun yang datang dari negeri-negeri Timur, semuanya diterima dengan melalui proses penyesuaian dengan kepribadian Rakyat Indonesia sendir

Power supply system for smart contact lens

The development of a smart contact lens is a promising aspect in wearable devices in the future for various medical applications. A major challenge that affects the development of smart contact lens is finding a suitable power supply that abides by the safety regulations imposed for wearable devices worn on the eye. The objective of this project is to study and fabricate an aqueous battery that is flexible and biocompatible to the human eye. The material used for the battery electrode is Prussian Blue Analogues (PBAs). The battery is designed to operate safely in a tear-based solution, similarly to the surrounding environment of the human eye. Cyclic voltammetry (CV) and galvanostatic cycling with potential limitation (GCPL) curve tests are used to evaluate the performance of the battery.Bachelor of Engineering (Electrical and Electronic Engineering