Grating-coupled external-cavity quantum-cascade lasers were studied for temperatures from 80 to 230 K. At 80 K, a tuning range of ∼65–88 nm are obtained for 4.5 and 5.1 μm laser amplifiers, respectively. The tuning ranges for both narrowed substantially with increasing temperature, to ∼23 nm at 203 K. The threshold varied slowly versus wavelength, while the efficiency appeared to be close to optimum toward wavelengths shorter than the free running wavelength.

Articles you may be interested inReliability of strain-balanced Ga 0.331 In 0.669 As ∕ Al 0.659 In 0.341 As ∕ In P quantum-cascade lasers under continuous-wave room-temperature operation High-temperature operation of distributed feedback quantum-cascade lasers at 5.3 μm Appl. Phys. Lett. 78, 396 (2001); 10.1063/1.1340865 Design considerations and analytical approximations for high continuous-wave power, broad-waveguide diode lasers Appl. Phys. Lett. 74, 3102 (1999); 10.1063/1.124075 High-temperature continuous-wave operation of λ8 μm quantum cascade lasers

It was previously reported that spectrally matched n-SiC and n-GaN-based MIS Schottky barrier diode structures exhibited optical emission and photosensitivity in the near-ultraviolet (UV) range of the spectrum and rectification at elevated temperatures. However, such structures were not practical due to the low mechanical and thermal stability of the semitransparent Au contacts. In addition, we experienced difficulties in achieving stable optical emission from the n-GaN-based structures. In this work various Schottky barrier diode structures based on p-type GaN layers grown on sapphire with silicon (Si), boron nitride (BN), and silicon dioxide (SiO2) interfacial layers were investigated. Blue and wide-spectrum optical emissions at forward and reverse bias, respectively, and photosensitivity were observed from these structures. A spectral match in the range of 365–400 nm between the light emitting diode (LED) and photodetector structures fabricated on the same substrate was achieved. A total Lambertian radiant UV power of ∼466 μW was measured from a blue/UV LED at 22 V. UV-transparent and electrically conductive SnOx layers were fabricated, characterized, and employed for fabrication of p-GaN-based photodiode structures.

No abstract

Articles you may be interested in2 μm laterally coupled distributed-feedback GaSb-based metamorphic laser grown on a GaAs substrate Appl. Phys. Lett. 102, 231101 (2013); 10.1063/1.4808265 Molecular beam epitaxy of InP-based alloys for long-wavelength vertical cavity lasers

Reliable, miniature, multifunctional, real-time optoelectronic sensors can be fabricated by using III nitride materials that have several advantages over the conventional semiconductors. Recent advances in these materials allow integrated optoelectronic devices with tunable spectral characteristics. In addition, optically transparent sapphire substrates and commercially beneficial silicon wafers can be used for the device fabrication. Two concepts of the integrated optoelectronic sensor development are presented in this work. These concepts were investigated by fabrication and testing simulators based on III nitride and Si commercial components. The fabricated devices exhibit multifunctionality expressed by the ability to perform measurements of optical absorption (metallic salts solutions), reflection (interface with commonly used solvents), scattering (alumina powder slurries), and fluorescence (chlorophyll, fluorescein, pyrene, anthracene, and Escherichia coli strains carrying plasmids which encode fluorescent proteins). These measurements indicate the applicability of the III nitride and Si-based components and their layout according to the described concepts for the development of integrated multifunctional optoelectronic sensors.

No abstract

11:30 am 8 MONDAY AFTERNOON / CLEO 2000 / 59 sys~cius. 'l'heicfnre it is iiiipiirhiit to understaiid tlic piilnrimtiuii evolutinn inside h p to pscdiit systeiii pcriolmancc and to develop accurate thcorclical iiidels. The signal's pii.proliagatiiig s t m d a r d solitons with p n l x i m t i m division iniiltiplcxing (1'1)M) has Iieen stiidied tl1coretic:illy :ind cxpcrimentally.' 1 l,iwevcr, dis~~c~siiin-~nan;igd solitons systems sigiiific;iiitly diilerrnt dynaniic cviilutioii. lii p d c u l a i , (lie t W noise build-up aallici iliaii tiining jitter limits Ihc winsmissinn ilislaucc.L I n our slud~cs, we tiillowed llie piiLirhtiiiii evolutiuii o l the iioisc as well as llic sigilal. A rcduccd model WIS iised to simulate tlic dynaniiu ,li l l i e polarization cvnlution. OIIL studies 01 the iruise dyi~omics have iinplicatiiins fin im-siilitoiis systciiis as wcll.