Limits...
Continuous-wave broadly tunable high-power Cr:CdS laser.

Sorokin E, Klimentov D, Frolov MP, Korostelin YV, Kozlovsky VI, Podmar'kov YP, Skasyrsky YK, Sorokina IT - Appl Phys B (2014)

Bottom Line: Lifetime values vary from 7.6 µs at 8 K to 0.48 µs at 320 K, corresponding to 22 % quantum yield at 285 K.Under Tm-fiber laser pumping, the continuous-wave output reached 1.8 W at 2.5 μm with 35.5 % slope efficiency.With a single CaF2 prism, the CW Cr(2+):CdS laser could be tuned from 2.240 to 3.285 µm.

View Article: PubMed Central - PubMed

Affiliation: Institut für Photonik, TU Wien, Gusshausstrasse 27/387, 1040 Vienna, Austria.

ABSTRACT

We report spectroscopic characteristics and laser properties of the mid-infrared active laser medium Cr(2+):CdS. Temperature-dependent absorption, luminescence and lifetime measurements of the (5)E exited state allow determination of peak emission cross section value of 1.35 × 10(-18) cm(2) in σ-polarization at room temperature. Lifetime values vary from 7.6 µs at 8 K to 0.48 µs at 320 K, corresponding to 22 % quantum yield at 285 K. Under Tm-fiber laser pumping, the continuous-wave output reached 1.8 W at 2.5 μm with 35.5 % slope efficiency. With a single CaF2 prism, the CW Cr(2+):CdS laser could be tuned from 2.240 to 3.285 µm.

No MeSH data available.


Output power of a continuous-wave Cr:CdS laser. The color insets show the mode intensity distribution at low, medium and high power
© Copyright Policy - OpenAccess
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4372838&req=5

Fig5: Output power of a continuous-wave Cr:CdS laser. The color insets show the mode intensity distribution at low, medium and high power

Mentions: Figure 5 shows the laser output characteristics measured with 6 % output coupler. Without wavelength selecting elements and purging, the laser operates between 2,540 and 2,555 nm. The laser output reached ~1.8 W at 6 W of absorbed power. To avoid the high reflector damage, the pump focus was moved away from the mirror. We measured slope efficiency of ~14 %, limited by the losses at the input face of the crystal (Fresnel reflection coefficient 15.2 %) and weak absorption of pump radiation by the crystal (46 %). With respect to the absorbed pump power, the slope efficiency reached 35.5 %. Even without polarizing elements in the cavity, the output radiation is mostly linearly polarized due to the slight misorientation of the c-axis. By rotating the sample, we made sure that this intrinsic polarization lies in the plane of Fig. 2. The mode profiles at the laser output (colored insets in Fig. 4) demonstrate building up of a cross-like shape at high power, typical for the induced birefringence influence. This is caused by the orientation of the active medium with the optical axis along the bam propagation direction. Orienting the optical axis perpendicular to the beam direction would allow using the intrinsic birefringence to suppress the thermal depolarization, and improve both the mode quality and efficiency.Fig. 5


Continuous-wave broadly tunable high-power Cr:CdS laser.

Sorokin E, Klimentov D, Frolov MP, Korostelin YV, Kozlovsky VI, Podmar'kov YP, Skasyrsky YK, Sorokina IT - Appl Phys B (2014)

Output power of a continuous-wave Cr:CdS laser. The color insets show the mode intensity distribution at low, medium and high power
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4372838&req=5

Fig5: Output power of a continuous-wave Cr:CdS laser. The color insets show the mode intensity distribution at low, medium and high power
Mentions: Figure 5 shows the laser output characteristics measured with 6 % output coupler. Without wavelength selecting elements and purging, the laser operates between 2,540 and 2,555 nm. The laser output reached ~1.8 W at 6 W of absorbed power. To avoid the high reflector damage, the pump focus was moved away from the mirror. We measured slope efficiency of ~14 %, limited by the losses at the input face of the crystal (Fresnel reflection coefficient 15.2 %) and weak absorption of pump radiation by the crystal (46 %). With respect to the absorbed pump power, the slope efficiency reached 35.5 %. Even without polarizing elements in the cavity, the output radiation is mostly linearly polarized due to the slight misorientation of the c-axis. By rotating the sample, we made sure that this intrinsic polarization lies in the plane of Fig. 2. The mode profiles at the laser output (colored insets in Fig. 4) demonstrate building up of a cross-like shape at high power, typical for the induced birefringence influence. This is caused by the orientation of the active medium with the optical axis along the bam propagation direction. Orienting the optical axis perpendicular to the beam direction would allow using the intrinsic birefringence to suppress the thermal depolarization, and improve both the mode quality and efficiency.Fig. 5

Bottom Line: Lifetime values vary from 7.6 µs at 8 K to 0.48 µs at 320 K, corresponding to 22 % quantum yield at 285 K.Under Tm-fiber laser pumping, the continuous-wave output reached 1.8 W at 2.5 μm with 35.5 % slope efficiency.With a single CaF2 prism, the CW Cr(2+):CdS laser could be tuned from 2.240 to 3.285 µm.

View Article: PubMed Central - PubMed

Affiliation: Institut für Photonik, TU Wien, Gusshausstrasse 27/387, 1040 Vienna, Austria.

ABSTRACT

We report spectroscopic characteristics and laser properties of the mid-infrared active laser medium Cr(2+):CdS. Temperature-dependent absorption, luminescence and lifetime measurements of the (5)E exited state allow determination of peak emission cross section value of 1.35 × 10(-18) cm(2) in σ-polarization at room temperature. Lifetime values vary from 7.6 µs at 8 K to 0.48 µs at 320 K, corresponding to 22 % quantum yield at 285 K. Under Tm-fiber laser pumping, the continuous-wave output reached 1.8 W at 2.5 μm with 35.5 % slope efficiency. With a single CaF2 prism, the CW Cr(2+):CdS laser could be tuned from 2.240 to 3.285 µm.

No MeSH data available.