Browsing by Author "Shieh, HM"

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Characteristics of monolithically integrated two-wavelength laser diodes with aluminum-free active layers
(2001-02-12)
Lu, TC
;
Fu, R
;
Shieh, HM
;
Huang, KJ
;
Wang, SC
A two-wavelength integrated laser diode (TWINLD) with aluminum-free active areas (AAA) has been realized by monolithically combining two different laser material structures in a single chip utilizing the metalorganic chemical vapor deposition growth and regrowth techniques. The single TWINLD chip comprises two ridge wave-guide lasers, one is an InGaP/InGaAlP material structure for a 650 nm red laser, and another is an InGaAsP/AlGaAs material structure with AAA for a 780 nm infrared laser. The chip geometry is 300 mum long and 300 mum wide with a separation of 150 mum between two laser emission spots. The ridge widths are 3.5 and 2 mum for the red and IR laser, respectively, and both lasers emit a single transverse mode with a threshold current of 12 mA for a 650 nm laser and 14 mA for a 780 nm laser under continuous wave operation condition. (C) 2001 American Institute of Physics.
Real index-guided InGaAlP red lasers with buried tunnel junctions
(2002-03-18)
Lu, TC
;
Shieh, HM
;
Wang, SC
;
光電工程學系
;
Department of Photonics
Real index-guided buried ridge InGaAlP 650 nm band lasers with p(+)-n(+) buried tunnel junctions are demonstrated. Located on top of the buried ridges, the tunnel junctions, made of InGaAs/GaAs superlattices with modulation doping, were introduced as the current injection window areas. The large band gap In0.5Al0.5P layers were directly regrown around the ridges using metalorganic chemical vapor deposition to serve as the current blocking layers. Real index optical waveguiding in the lateral direction was also provided by the smaller refractive index of In0.5Al0.5P layers. The lasers showed lower threshold current and higher slope efficiency compared to conventional complex index-guided InGaAlP lasers with GaAs current blocking layers, and had low internal loss of about 5.4 cm(-1). (C) 2002 American Institute of Physics.