TY - JOUR
T1 - 830nm graded index double barrier separate confinement heterostructure laser diodes with small vertical divergence and temperature insensitive characteristics
AU - Hung, Chih Tsang
AU - Ho, Tsong Lin
AU - Lu, Tien-chang
PY - 2012/10/9
Y1 - 2012/10/9
N2 - Semiconductor laser diodes (LDs) are preferred as pump sources for many solid state laser systems. However, these applications require mainly high output power and narrow beam divergence of LDs to achieve high conversion and coupling efficiencies. Widening the transverse mode to reduce power density at the facet is one direct approaching to increase the catastrophic optical damage (COD). A reduced optical confinement factor can be naturally obtained in lasers with wide waveguides, providing narrow far field emission [1]. Various optimizing methods of laser heterostructures focus on the beam divergence reduction and then contribute to high COD level. Unfortunately, a decrease of the confinement factor is inevitably connected with a deterioration of the laser performance, such as threshold current, slop efficiency, and maximum output power. Several designs have been proposed to mitigate these side effects, such as utilization of a large optical cavity (LOC) into separate-confinement heterostructure (SCH) layers [2], inserting additional layers to control waveguide properties of conventional SCHs [3], or using the vertically integrated passive array [4]. A main disadvantage of LOC design is, however, the deterioration of the laser diode performance as waveguide layers are modified excessively thick to reach very high power operation. Compared with the LOC structure into SCH LDs, the LDs with the double barrier separate-confinement heterostructure (DBSCH) structure possess superior characteristics in both COD levels and beam divergence with only moderate deterioration of LD performance in slope efficiency and characteristic temperature [5]. For DBSCH LDs, pair of wide-gap barrier layers which possess low refractive index are inserted into the interfaces between the waveguide and cladding layers, which will widen the transverse mode by modifying the epitaxial layers of double barriers (DBs).
AB - Semiconductor laser diodes (LDs) are preferred as pump sources for many solid state laser systems. However, these applications require mainly high output power and narrow beam divergence of LDs to achieve high conversion and coupling efficiencies. Widening the transverse mode to reduce power density at the facet is one direct approaching to increase the catastrophic optical damage (COD). A reduced optical confinement factor can be naturally obtained in lasers with wide waveguides, providing narrow far field emission [1]. Various optimizing methods of laser heterostructures focus on the beam divergence reduction and then contribute to high COD level. Unfortunately, a decrease of the confinement factor is inevitably connected with a deterioration of the laser performance, such as threshold current, slop efficiency, and maximum output power. Several designs have been proposed to mitigate these side effects, such as utilization of a large optical cavity (LOC) into separate-confinement heterostructure (SCH) layers [2], inserting additional layers to control waveguide properties of conventional SCHs [3], or using the vertically integrated passive array [4]. A main disadvantage of LOC design is, however, the deterioration of the laser diode performance as waveguide layers are modified excessively thick to reach very high power operation. Compared with the LOC structure into SCH LDs, the LDs with the double barrier separate-confinement heterostructure (DBSCH) structure possess superior characteristics in both COD levels and beam divergence with only moderate deterioration of LD performance in slope efficiency and characteristic temperature [5]. For DBSCH LDs, pair of wide-gap barrier layers which possess low refractive index are inserted into the interfaces between the waveguide and cladding layers, which will widen the transverse mode by modifying the epitaxial layers of double barriers (DBs).
UR - http://www.scopus.com/inward/record.url?scp=84870587401&partnerID=8YFLogxK
U2 - 10.1109/ISLC.2012.6348342
DO - 10.1109/ISLC.2012.6348342
M3 - Conference article
AN - SCOPUS:84870587401
SN - 0899-9406
SP - 76
EP - 77
JO - Conference Digest - IEEE International Semiconductor Laser Conference
JF - Conference Digest - IEEE International Semiconductor Laser Conference
M1 - 6348342
T2 - 23rd IEEE International Semiconductor Laser Conference, ISLC 2012
Y2 - 7 October 2012 through 10 October 2012
ER -