the modulation response, relative intensity noise and frequency noise characteristics of qd lasers are investigated theoretically, in presence of an additional optical pumping. it is revealed that the modulation response of qd laser enhances under additional optical beam. by small signal analysis of the carriers' and photons' rates, it is proposed that by injecting excess carriers to ...

In the present work,MoS2 decorated graphene nanocomposite powders were synthesized by laser scribing method.Theobtainedflexible light-scribed graphene/MoS2composites are very suitableas micro-supercapacitors and thus their performance was evaluated at different concentrations.The effect of laser scribing process to reducegraphene oxide (GO) was investigated. The GO/MoS2composite wassynthesized ...

We present a novel slanted faces of thin-disk composite Yb:YAG YAG laser which is side-pumped by four non-symmetric hollow- ducts. The pump light distribution in the disk is modeled by using Monte-Carlo ray tracing method. The temperature distribution inside the crystal is calculated by taking into account either the concentration of Yb+3 ion or the different transmission of laser output coupl...

Seventeen two-photon transitions for neon have been observed in the 580- 635 nm spectral region for use in the spectroscopic study of its higher excited levels, which are not accessible by one-photon absorption. To compare the two and one-photon absorption signals originating from the same lower level, an effort was made to record single-photon optogalvanic spectrum in the available wavele...

aim and background:   knee osteoarthritis (oa) is a prevalent and disabling disease. periarticular corticosteroid injection has been traditionally used for the pain control in these patients. recently low power laser has been introduced as a therapeutic option. this study was conducted to evaluate the efficacy of low power laser added to periarticular steroid injection for long-term treatment o...

introduction :the aim of this study was to evaluate and compare the in vitro effect of the erbium-doped yttrium aluminum garnet (er:yag) laser with different radiation distances and high-speed rotary treatment on the shear bond strength of flowable composite to enamel of human permanent posterior teeth . methods : freshly extracted human molar teeth with no caries or other surface defects were ...

Objectives: The purpose of this in vitro study was to evaluate the microleakage of cervical cavities prepared by Er:YAG laser or high-speed hand piece and bur. Methods: This in vitro experimental study was performed on 40 sound permanent third molar teeth randomly assigned into two equal groups (n=20). In the first group, high-speed hand piece and bur and in the second group Er:YAG la...

In this paper, we present a high accuracy laser range finder and velocimeter using ultra-fast time-to-digital converter (TDC). The system operation is based on the measuring the round-trip time of a narrow laser pulse. A low-dark current high-speed PIN photodiode is used to detect the triggered laser beam and to produce start signal. The pulsed laser diode generates 45W optical power at 30ns du...