High-power continuous-wave mid-infrared difference-frequency generation in the presence of thermal effects

Abstract

We report performance studies of high-power, continuous-wave (cw), mid-infrared (mid-IR) difference-frequency generation (DFG) in MgO:PPLN at 2262 nm based on a narrowband Yb-fiber laser as pump and a Tm-fiber laser as signal source. Using a 50-mm-long crystal, we generate as much as 3.84 W of DFG output power at a single-pass conversion efficiency up to 0.57%/W, with a passive power stability better than 0.53% rms and passive spectral stability better than 0.01% over 1 h. The DFG beam also exhibits excellent spatial beam quality in T E M 00 mode profile with M 2 &lt;<!-- 1.2 , and a beam pointing stability better than 16 µrad over &gt; 1 h . Simulations based on focused Gaussian beam theory provide an accurate estimate of the generated DFG output power and confirm thermal effects. Detailed thermal analysis indicates the role of linear absorption at the interacting wavelengths in local heating within the focal volume of the MgO:PPLN crystal. To the best of our knowledge, this is the highest cw DFG output power and conversion efficiency achieved in bulk MgO:PPLN in the mid-IR.

Recent Advances in χ (2) ‐Based Nonlinear Frequency Conversion of Fiber Lasers

“…[ 15 ] In addition, thulium‐doped fiber lasers (TFLs) emitting at 2.010 μm, in combination with YFLs emitting at 1.064 μm, can be used for DFG in the PPLN crystals to produce MIR lasing radiation at 2.26 μm. [ 73,74 ] Moreover, Q‐switched TFLs operating can serve as the effective pump sources for orientation‐patterned galliumarsenide (OP‐GaAs) crystal‐based OPO systems. [ 75,76 ] In work done by Wueppen et al, [ 75 ] the 1.95 μm TFL‐pumped OPO system can generate idler lasing with a wavelength of ≈10.6 μm, an average output power of 800 mW, and a conversion efficiency of 36.8%.…”

Recent Advances in χ (2) ‐Based Nonlinear Frequency Conversion of Fiber Lasers

“…[ 15 ] In addition, thulium‐doped fiber lasers (TFLs) emitting at 2.010 μm, in combination with YFLs emitting at 1.064 μm, can be used for DFG in the PPLN crystals to produce MIR lasing radiation at 2.26 μm. [ 73,74 ] Moreover, Q‐switched TFLs operating can serve as the effective pump sources for orientation‐patterned galliumarsenide (OP‐GaAs) crystal‐based OPO systems. [ 75,76 ] In work done by Wueppen et al, [ 75 ] the 1.95 μm TFL‐pumped OPO system can generate idler lasing with a wavelength of ≈10.6 μm, an average output power of 800 mW, and a conversion efficiency of 36.8%.…”

Single-frequency mid-infrared source based on unidirectional ring-laser exploiting differential parametric gain from tunable, single-frequency pump source

“…In this demonstration, the solid-state ring laser emitted single-frequency output and simultaneously, the DFG between the solid-state laser and the injected tunable diode laser generated tunable single-frequency light in the 3000 nm wavelength range. DFG is generally used to generate tunable mid-infrared light, where different approaches have been demonstrated with both single-pass and intracavity implementations 8,9 . By simultaneously tuning one of the interacting lasers and assuring phase matching, large tuning ranges can be achieved, typically limited only by the tuning range of the tunable laser.…”

Mid-infrared difference-frequency generation in AlGaAs-on-insulator waveguides

“…To create such a device the proper material and platform must be chosen. Promising materials for frequency conversion include lithium niobate for spontaneous parametric down-conversion, second-harmonic generation (SHG) [20][21][22][23], and difference-frequency generation (DFG), where, to our knowledge, periodic poling is required to achieve quasi-phase matching [24,25]. Other materials include AlN [26], GaP [27] and GaN [28], which may also be viable options for on-chip frequency conversion.…”

Recent Advances in χ (2) ‐Based Nonlinear Frequency Conversion of Fiber Lasers

“…[ 15 ] In addition, thulium‐doped fiber lasers (TFLs) emitting at 2.010 μm, in combination with YFLs emitting at 1.064 μm, can be used for DFG in the PPLN crystals to produce MIR lasing radiation at 2.26 μm. [ 73,74 ] Moreover, Q‐switched TFLs operating can serve as the effective pump sources for orientation‐patterned galliumarsenide (OP‐GaAs) crystal‐based OPO systems. [ 75,76 ] In work done by Wueppen et al, [ 75 ] the 1.95 μm TFL‐pumped OPO system can generate idler lasing with a wavelength of ≈10.6 μm, an average output power of 800 mW, and a conversion efficiency of 36.8%.…”

Single-frequency mid-infrared source based on unidirectional ring-laser exploiting differential parametric gain from tunable, single-frequency pump source

“…In this demonstration, the solid-state ring laser emitted single-frequency output and simultaneously, the DFG between the solid-state laser and the injected tunable diode laser generated tunable single-frequency light in the 3000 nm wavelength range. DFG is generally used to generate tunable mid-infrared light, where different approaches have been demonstrated with both single-pass and intracavity implementations 8,9 . By simultaneously tuning one of the interacting lasers and assuring phase matching, large tuning ranges can be achieved, typically limited only by the tuning range of the tunable laser.…”

Mid-infrared difference-frequency generation in AlGaAs-on-insulator waveguides

“…To create such a device the proper material and platform must be chosen. Promising materials for frequency conversion include lithium niobate for spontaneous parametric down-conversion, second-harmonic generation (SHG) [20][21][22][23], and difference-frequency generation (DFG), where, to our knowledge, periodic poling is required to achieve quasi-phase matching [24,25]. Other materials include AlN [26], GaP [27] and GaN [28], which may also be viable options for on-chip frequency conversion.…”

Recent Advances in χ (2) ‐Based Nonlinear Frequency Conversion of Fiber Lasers

“…[ 15 ] In addition, thulium‐doped fiber lasers (TFLs) emitting at 2.010 μm, in combination with YFLs emitting at 1.064 μm, can be used for DFG in the PPLN crystals to produce MIR lasing radiation at 2.26 μm. [ 73,74 ] Moreover, Q‐switched TFLs operating can serve as the effective pump sources for orientation‐patterned galliumarsenide (OP‐GaAs) crystal‐based OPO systems. [ 75,76 ] In work done by Wueppen et al, [ 75 ] the 1.95 μm TFL‐pumped OPO system can generate idler lasing with a wavelength of ≈10.6 μm, an average output power of 800 mW, and a conversion efficiency of 36.8%.…”

Single-frequency mid-infrared source based on unidirectional ring-laser exploiting differential parametric gain from tunable, single-frequency pump source

“…In this demonstration, the solid-state ring laser emitted single-frequency output and simultaneously, the DFG between the solid-state laser and the injected tunable diode laser generated tunable single-frequency light in the 3000 nm wavelength range. DFG is generally used to generate tunable mid-infrared light, where different approaches have been demonstrated with both single-pass and intracavity implementations 8,9 . By simultaneously tuning one of the interacting lasers and assuring phase matching, large tuning ranges can be achieved, typically limited only by the tuning range of the tunable laser.…”

Mid-infrared difference-frequency generation in AlGaAs-on-insulator waveguides

“…To create such a device the proper material and platform must be chosen. Promising materials for frequency conversion include lithium niobate for spontaneous parametric down-conversion, second-harmonic generation (SHG) [20][21][22][23], and difference-frequency generation (DFG), where, to our knowledge, periodic poling is required to achieve quasi-phase matching [24,25]. Other materials include AlN [26], GaP [27] and GaN [28], which may also be viable options for on-chip frequency conversion.…”