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10-W pulsed operation of substrate emitting photonic-crystal quantum cascade laser with very small divergence.

Yao DY, Zhang JC, Cathabard O, Zhai SQ, Liu YH, Jia ZW, Liu FQ, Wang ZG - Nanoscale Res Lett (2015)

Bottom Line: High-power broad area substrate emitting photonic-crystal distributed feedback (DFB) quantum cascade lasers (QCLs) emitting around 4.73 μm is reported.Two-dimensional centered rectangular photonic-crystal (CRPC) grating is introduced to enhance optical coherence in large area device.Main lobe far-field radiation pattern with a very small divergence angle of about 0.65° × 0.31° is obtained.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing, 100083 China.

ABSTRACT
High-power broad area substrate emitting photonic-crystal distributed feedback (DFB) quantum cascade lasers (QCLs) emitting around 4.73 μm is reported. Two-dimensional centered rectangular photonic-crystal (CRPC) grating is introduced to enhance optical coherence in large area device. Main lobe far-field radiation pattern with a very small divergence angle of about 0.65° × 0.31° is obtained. A record peak output power for vertical emitting QCLs exceeding 10 W is obtained with high reflectivity (HR) coating. Robust single longitudinal mode emission with a side mode suppression ratio (SMSR) of 30 dB is continuously tunable by the heat sink temperature up to 65°C.

No MeSH data available.


Related in: MedlinePlus

Band structure near the Γ point of lattice PC. With cross angle θ ranging from (a) 90°, square lattice. (b) 80° and (c) 70°, in turn, centered rectangular lattice. (d) 60°, hexagonal lattice.
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Fig2: Band structure near the Γ point of lattice PC. With cross angle θ ranging from (a) 90°, square lattice. (b) 80° and (c) 70°, in turn, centered rectangular lattice. (d) 60°, hexagonal lattice.

Mentions: By using bandsolve module of Rsoft, based on 2D plane wave (PW) expansion method [24], we first analyze the band structure for different types of lattice and calculate the number of band edge longitudinal modes simultaneously. Figure 2 shows the enlarged band structure near the Γ point of lattice PC with cross angle θ ranging from 90° to 60° in a step of 10°, and the insets at the bottom of each picture depict the pattern of different types of photonic-crystal. The number of band edge resonant fundamental longitudinal mode depends on the lattice structure. There are both four modes for square (Figure 2a) and centered rectangular lattice (Figure 2b,c) while six modes presented for hexagonal lattice (Figure 2d). It indicates that square and centered rectangular lattices are more likely to realize stable single longitudinal mode oscillation.Figure 2


10-W pulsed operation of substrate emitting photonic-crystal quantum cascade laser with very small divergence.

Yao DY, Zhang JC, Cathabard O, Zhai SQ, Liu YH, Jia ZW, Liu FQ, Wang ZG - Nanoscale Res Lett (2015)

Band structure near the Γ point of lattice PC. With cross angle θ ranging from (a) 90°, square lattice. (b) 80° and (c) 70°, in turn, centered rectangular lattice. (d) 60°, hexagonal lattice.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4402689&req=5

Fig2: Band structure near the Γ point of lattice PC. With cross angle θ ranging from (a) 90°, square lattice. (b) 80° and (c) 70°, in turn, centered rectangular lattice. (d) 60°, hexagonal lattice.
Mentions: By using bandsolve module of Rsoft, based on 2D plane wave (PW) expansion method [24], we first analyze the band structure for different types of lattice and calculate the number of band edge longitudinal modes simultaneously. Figure 2 shows the enlarged band structure near the Γ point of lattice PC with cross angle θ ranging from 90° to 60° in a step of 10°, and the insets at the bottom of each picture depict the pattern of different types of photonic-crystal. The number of band edge resonant fundamental longitudinal mode depends on the lattice structure. There are both four modes for square (Figure 2a) and centered rectangular lattice (Figure 2b,c) while six modes presented for hexagonal lattice (Figure 2d). It indicates that square and centered rectangular lattices are more likely to realize stable single longitudinal mode oscillation.Figure 2

Bottom Line: High-power broad area substrate emitting photonic-crystal distributed feedback (DFB) quantum cascade lasers (QCLs) emitting around 4.73 μm is reported.Two-dimensional centered rectangular photonic-crystal (CRPC) grating is introduced to enhance optical coherence in large area device.Main lobe far-field radiation pattern with a very small divergence angle of about 0.65° × 0.31° is obtained.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing, 100083 China.

ABSTRACT
High-power broad area substrate emitting photonic-crystal distributed feedback (DFB) quantum cascade lasers (QCLs) emitting around 4.73 μm is reported. Two-dimensional centered rectangular photonic-crystal (CRPC) grating is introduced to enhance optical coherence in large area device. Main lobe far-field radiation pattern with a very small divergence angle of about 0.65° × 0.31° is obtained. A record peak output power for vertical emitting QCLs exceeding 10 W is obtained with high reflectivity (HR) coating. Robust single longitudinal mode emission with a side mode suppression ratio (SMSR) of 30 dB is continuously tunable by the heat sink temperature up to 65°C.

No MeSH data available.


Related in: MedlinePlus