Characteristics of InGaN Multiquantum-Well-Structure Laser Diodes

1996 ◽  
Vol 449 ◽  
Author(s):  
Shuji Nakamura

ABSTRACTThe continuous-wave (CW) operation of InGaN multi-quantum-well-structure laser diodes (LDs) was demonstrated at room temperature (RT) with a lifetime of 35 hours. The threshold current and the voltage of the LDs were 80 mA and 5.5 V, respectively. The threshold current density was 3.6 kA/cm2. Longitudinal modes with a mode separation of 0.042 nm were observed under CW operation at RT. When the temperature of the LDs was varied, large mode hopping of the emission wavelength was observed. The carrier lifetime and the threshold carrier density were estimated to be 10 ns and 2 × 1020/cm3, respectively. The beam full width at half-power values for the parallel and the perpendicular near-field patterns were 1.6 µm and 0.8 µm, respectively. Those of the far-field patterns were 6.8° and 33.6°, respectively.

Author(s):  
Shuji Nakamura

The continuous-wave (CW) operation of InGaN multi-quantum-well-structure laser diodes (LDs) was demonstrated at room temperature (RT) with a lifetime of 35 hours. The threshold current and the voltage of the LDs were 80 mA and 5.5 V, respectively. The threshold current density was 3.6 kA/cm2. When the temperature of the LDs was varied, large mode hopping of the emission wavelength was observed. The carrier lifetime and the threshold carrier density were estimated to be 2-10 ns and 1-2 × 1020/cm3, respectively. From the measurements of gain spectra and an external differential quantum efficiency dependence on the cavity length, the differential gain coefficient, the transparent carrier density, threshold gain and internal loss were estimated to be 5.8×10−17 cm2, 9.3×1019 cm−3, 5200 cm−1 and 43 cm−1, respectively.


2000 ◽  
Vol 5 (S1) ◽  
pp. 1-7 ◽  
Author(s):  
Masayoshi Koike ◽  
Shiro Yamasaki ◽  
Yuta Tezen ◽  
Seiji Nagai ◽  
Sho Iwayama ◽  
...  

GaN-based short wavelength laser diodes are the most promising key device for a digital versatile disk. We have been improving the important points of the laser diodes in terms of optical guiding layers, mirror facets. The continuous wave laser irradiation at room temperature could be achieved successfully by reducing the threshold current to 60 mA (4 kA/cm2). We have tried to apply the multi low temperature buffer layers to the laser diodes for the first time to reduce the crystal defects.


2011 ◽  
Vol 20 (03) ◽  
pp. 515-520
Author(s):  
Y. ZHANG ◽  
J.-P. LIU ◽  
T.-T. KAO ◽  
S. KIM ◽  
Y.-C. LEE ◽  
...  

A step-graded Al x Ga 1- x N electron blocking layer (EBL) is introduced to the InGaN -based edge-emitting blue-violet laser diode (LD) structure to suppress the undesired built-in interface polarization charges. When compared to a conventional abrupt Al 0.18 Ga 0.82 N EBL design, the step-graded Al x Ga 1- x N EBL design may help reduce the electron accumulation at the edge of the active region and hence improve the quantum efficiency in LD operation. The effects of the step-graded Al x Ga 1- x N EBL on the fabricated device performance are also investigated. LDs with the step-graded Al x Ga 1- x N EBL demonstrated significantly reduced threshold current density and increased slope efficiency under the continuous-wave operation.


1999 ◽  
Vol 595 ◽  
Author(s):  
Masayoshi Koike ◽  
Shiro Yamasaki ◽  
Yuta Tezen ◽  
Seiji Nagai ◽  
Sho Iwayama ◽  
...  

AbstractGaN-based short wavelength laser diodes are the most promising key device for a digital versatile disk. We have been improving the important points of the laser diodes in terms of optical guiding layers, mirror facets. The continuous wave laser irradiation at room temperature could be achieved successfully by reducing the threshold current to 60 mA (4 kA/cm2). We have tried to apply the multi low temperature buffer layers to the laser diodes for the first time to reduce the crystal defects.


1999 ◽  
Vol 14 (7) ◽  
pp. 2716-2731 ◽  
Author(s):  
Shuji Nakamura

Epitaxially laterally overgrown GaN on sapphire was used to reduce the number of threading dislocations originating from the interface of the GaN epilayer with the sapphire substrate. The GaN layer above the SiO2 mask area surrounding the window and corresponding to the lateral overgrowth was nearly free of threading dislocations. A high density of threading dislocations was observed in the vicinity of GaN grown in the window regions. InGaN multiquantum well-structure laser diodes (LDs) grown on pure GaN substrates, which were fabricated by removing the sapphire substrate, were demonstrated. The LDs with an output power of 5 mW exhibited a lifetime of more than 290 h and an estimated lifetime of 10,000 h despite a relatively large threshold current density. The far-field pattern of the LDs with a cleaved mirror facet revealed single-mode emission without any interference effects.


1993 ◽  
Vol 300 ◽  
Author(s):  
Ph. Maurel ◽  
J.C. Garcia ◽  
J.P. Hirtz ◽  
E. Vassilakis ◽  
M. Baldy ◽  
...  

ABSTRACTGaInAs/GaAs/GaInP multiquantum well laser structures have been grown by chemical beam epitaxy (CBE) using conventional sources (hydrides as group V element sources). Large area lasers were photolitographically defined and mounted for continuous wave (CW) measurements. CW output power levels of 600 mW at 25°C are reported from 100 μm wide, 300 μm long laser diodes without any facet treatment. At these levels, the delivered current is 2A, with an associated voltage of less than 1.7 V. The characteristic temperature of the structure is 95 K.The same structures were then grown using tertiarybutylarsine (TBAs) and tertiarybutylphosphine (TBP). The large area laser diodes were characterized under pulsed conditions. For a 300 μm long cavity, threshold current density of 390 A/cm2 and external quantum efficiency of 0.6 W/A (2 facets) were obtained, demonstrating the suitability of TBP and TBAs as substitutes of arsine and phosphine in chemical beam epitaxy for laser fabrication.


2010 ◽  
Vol 3 (9) ◽  
pp. 091201 ◽  
Author(s):  
Jun-ichi Kasai ◽  
Ryouichi Akimoto ◽  
Haruhiko Kuwatsuka ◽  
Toshifumi Hasama ◽  
Hiroshi Ishikawa ◽  
...  

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