Three types of light sources based on superluminescent diodes (SLDs) of NIR ranges 800 – 880 nm and 860 – 950 nm with spatially single mode active channels were studied. Light-emitting modules have demonstrated free space continuous wave (CW) output power of up to 150 mW and 75 mW ex single mode optical fiber (SMF), at spectral bandwidth of about 25 nm. Master Oscillator Power Amplifier (MOPA) system in which SLD of the first type was used as an active element of a power amplifier and blue-shifted SLD as a master oscillator permitted to broaden spectral bandwidth up to 50 nm at the same output optical power level. The estimated lifetime of these devices is more than 10000 hours. High power combined light source based on two MOPA systems with spectral FWHM of more than 100 nm was realized.
Superluminescent diodes (SLDs) of spectral range 730 – 790 nm with strained single quantum-well (SQW) active layer and spatially single mode ridge waveguide were studied experimentally. SLDs with short active channels < 1000 μm have demonstrated broadband emission spectrum with median wavelength near 765 nm, FWHM of up to 60 nm and free space CW output power in the range 2 – 15 mW at 25°C. SLDs with longer active channels have demonstrated output of up to 150 mW and spectral half-width in the range 40 – 20 nm. TM mode was dominant in output emission.
Tunable semiconductor laser in red visible spectral range of 670-690 nm is investigated. Swept laser is based on a recently developed traveling wave semiconductor optical amplifier (SOA) of red spectral range as an active element and an acousto-optic tunable filter (AOTF) in an external fiber ring cavity. Tuning band of up to 20 nm, spectral linewidth below 0.04 nm, sweep speed of up to 104 nm/s and CW output power of up to 2.0 mW are obtained. Master-Oscillator Power Amplifier (MOPA) system permitted to increase the output power up to 15 mW with a laser used as a master oscillator and an external SOA - as a power amplifier. We believe the red source may find applications in swept source optical coherence tomography.
The optimization of AlGaInP/GaInPAs MQW heterostructure MOCVD growth as well as the improvements of active channel formation and P-contact deposition technologies made it possible to increase significantly external differential efficiency (up to 0.5 mW/mA) and CW catastrophic optical damage threshold (up to 40 mW) of spatially single-mode superluminescent diodes (SLDs) with central wavelength of 675 nm. Preliminary life time tests demonstrated high reliability of the devices at output power 30 mW. The relations of spectral and power characteristics of the SLDs as well as SLDs with central wavelengths of about 660 nm and 690 nm on active channel length, pumping level and temperature were studied. The results of mathematical modeling of combined light sources output parameters that could be made with SLDs and a broadband SM fiber coupler, are presented.
We report all-PM-fiber ring external cavity, extremely wide tunable/swept lasers and MOPA sources basing on a newly
developed SOAs and acousto-optic filter. Tuning ranges of 100 nm, 90 nm and 70 nm have been achieved at output
powers of 1.0 mW, 5.0 mW and 10.0 mW, respectively. Instantaneous linewidth below 0.04 nm and sweeping rate up to
104 nm/s had been demonstrated. Power boosting up to 50 mW (PMF) and up to 250 mW (MMF) with tunability of
around 50 nm had been also demonstrated by using MOPA systems basing on developed laser and different types of