Yadav Deepika, Ghosh Anirban, Saripalli Ravi K, Samanta G K
Opt Lett. 2020 Sep 15;45(18):5109-5112. doi: 10.1364/OL.404358.
We report a compact source of high power, tunable, ultrafast yellow radiation using fourth-harmonic generation of a mid-IR laser in two-stage frequency-doubling processes. Using : laser at 2360 nm frequency-doubled in a multi-grating MgO:PPLN crystal, we have generated near-IR radiation tunable across 1137-1200 nm with average output power as high as 2.4 W and pulse width of ∼60. Subsequently, the near-IR radiation is frequency-doubled using a bismuth triborate (BIBO) crystal to produce coherent yellow radiation tunable across 570-596 nm with a maximum average power of ∼1. The source has a maximum mid-IR to yellow (near-IR to yellow) single-pass conversion efficiency as high as ∼29.4 (∼47). Without any pulse compression, the yellow source has output pulses at a repetition rate of 80 MHz with a pulse width of ∼130 in Gaussian-shaped and a spectral width of ∼4 corresponding to a time-bandwidth product of 0.45. The generated output beam has a Gaussian transverse beam profile with measured values of 2∼1.07 and2∼1.01.
我们报道了一种紧凑的高功率、可调谐、超快黄色辐射源，它通过在两级倍频过程中对中红外激光进行四阶谐波产生。使用在多光栅MgO:PPLN晶体中倍频至2360 nm的激光，我们产生了波长在1137 - 1200 nm范围内可调谐的近红外辐射，平均输出功率高达2.4 W，脉冲宽度约为60。随后，使用硼酸铋（BIBO）晶体对近红外辐射进行倍频，以产生波长在570 - 596 nm范围内可调谐的相干黄色辐射，最大平均功率约为1。该光源的最大中红外到黄色（近红外到黄色）单通转换效率高达约29.4（约47）。在没有任何脉冲压缩的情况下，黄色光源输出重复频率为80 MHz的脉冲，高斯形状下脉冲宽度约为130，光谱宽度约为4，对应时间带宽积为0.45。所产生的输出光束具有高斯横向光束轮廓，测量值为2∼1.07和2∼1.01。
