650 nm GalnP/AlGaInP laser diodes with low threshold and compressively strained MQW active layer

650 nm AIGalnP/GalnP laser diodes with compressively strained MQW active layer have been successfully fabricated by means of single epitaxy growth. The threshold current is 6.4 mA,at 40 mA CW operation, the fundamental transverse-mode still remains, and the output power and the slope efficiency can reach 34 mW and 1.1 mW/mA respectively. The dead output power in CW operation can reach 66 mW at a saturation current of 88 mA. During 200 h burn in test,the laser diodes show good stabilization with a degradation of less than 8 %.     

Dependence of the propagation characteristics of buried channel glass waveguides on the fabrication parameters

Based on the variational analysis of the Er^＊-Yb^＊ co-doped glass optical waveguide,the dependence of the mode profiles and propagation characteristics on the fabrication parameters, mainly on the channel waveguide width and the annealing time, are investigated. Different influences of these parameters on the mode dimensions, the center position of the depth field profile, the effective refractive index, and overlap factor are shown in this letter, according to which the appropriate preparation conditions can be chosen.     

Effect of exit and injection rates on phase-dependent transient evolution of gain without inversion

It is shown that in an open Λ-type system with spontaneously generated coherence, the transient evolution rule of the gain of lasing without inversion (LWI) is very sensitive to variation of the relative phase φ between the probe and driving fields; the variety of the atomic exit rateγ_0 and the ratio C of the atomic injection rates also have a considerable effect on the phase-dependent transient evolution rule of LWI gain. We find that whenφ=0, the transient and stationary LWI gain increases with C increasing but decreases with γ_0 increasing; whenφ≠0 , the effect of C andγ_0 on LWI gain is just opposite to that when φ=0 ; in order to get the largest transient and stationary LWI gain, we need selecting suitable values of φ,γ_0 and C.     

Photoluminescence origin of nanocrystalline SiC films

The nanocrystalline SiC films were prepared on Si then annealed at 800℃ and 1 000℃ for 30 minutes （111） substrates by rf magnetron sputtering and in a vacuum annealing system. The crystal structure and crystallization of as-annealed SiC films were determined by the Fourier transform infrared （FIR） absorption spectra and the X-ray diffraction （XRD） analysis. Measurement of photoluminescence （PL） of the nanocrystalline SiC （nc-SiC） films shows that the blue light with 473 nm and 477 nm wavelengths emitted at room temperature and that the PL peak shifts to shorter wavelength side and the PL intensity becomes stronger as the annealing temperature decreases. The time-resolved spectrum of the PL at 477 nm exhibits a bi-exponential decay process with lifetimes of 600 ps and 5 ns and a characteristic of the direct band gap. The strong blue light emission with short PL lifetimes suggests that the quantum confinement effect of the SiC nanocrystals resulted in the radiative recombination of the direct optical transitions.     

Digital driver for 2-inch LTPS AM-OLED displays

Organiclightemittingdiode(OLED)displayshave beenattractingmoreattentionbecauseoftheirvariousadvantagesincludingsimplestructure,self emitting,fast responsetimeandwideviewingangle.Inthelastdec ade,thefocusofresearchisonimprovementofefficiency andreliability…     

Design of coating for broadband polarization- independent beam splitters and analysis of its optical performance

Thebeamsplitters(BS)havedemonstratedwideap plicationinmanyopticalsystemsandplayakeyrolein interferometryandholography[1].ThemechanismofBScanbedividedintotwocategories:oneutilizesthereflec tionandrefractionontheinterfacebetweentwodielec tricmedia;theotheru…     

PCCC for the performance improvement of the wireless optical communication system

Opticalwireless,alsoknownasfree spaceoptics,isa cost effectiveandwidebandwidthaccesstechniqueandreceivesgrowingattentionwithrecentcommercialization success.Buttheperformanceofwirelessopticalcommu nicationwouldbeimpairedintheatmosphericchannelbyattenuation…     

Organic light-emitting devices based on new rare earth complex Tb（p-CIBA）3phen

A new rare earth complex Tb（p-CIBA）3phen was synthesized and introduced into organic tight emitting devices （OLEDs） as emitting material. The Tb（p-CIBA）3phen was doped into PVK to improve the filmforming and hole-transporting property. Two kinds of devices were fabricated. The device structure is as the following. Single-layer device： ITO/PVK： Tb （p-CIBA） 3 phen /LiF/Al; double-layer device： ITO/PVK： Tb（p-CIBA）3phen/AIQ/LiF/AI. The performances of both devices were investigated carefully. We found that the emission of PVK was completely restrained,and only the green emission was observed from the electroluminescence. The full width at half maximum （FWHM） was less than 10 nm. The highest EL brighthess of the single-layer device is 25.4 cd/cm^2 at a fixed bias of 18 V,and the highest EL brightness of the double-layer device reaches 234.8 cd/cm^2 at a voltage of 20 V.     

S-band gain flattened distributed fiber Raman amplifier with chirped fiber bragg grating filter

IPTV,video-phone,video-conference,distance learn-ing,distance medical ,e-governmental affairs ,etc .will be-come commonthings in people' s daily life with the fastdevelopment of Internet technology.During this processextra-capacity of fiber communication …     

Channel Arrangement for optical communication subsystems with 12 parallel channels

This paper devoted to report the design and the achievement of an optical communication subsystem with 12 parallel channels in one chip. The system is capable of,transmitting 10 Gbps bidirectional date over hundreds of meters. It can provide error detection and correction by using 8B/10B encoding and Cyclical Redundancy Checking （CRC） encoding when only single-channel fails. The design scheme has already passed the simulation in FPGA. This technique is useful to enhance the capability and the reliability of the very short reach （VSR） transmission systems.