SSO Laser Research Articles

Two‐dimensional graphdiyne for passively Q‐switched Yb3+:Sc2SiO5 laser

AbstractIn this article, we demonstrate a laser diode pumped passively Q‐switched Yb3+:Sc2SiO5 (Yb:SSO) laser for the first time, applying a graphdiyne (GDY) saturable absorber which was prepared by the liquid phase exfoliation method. Utilizing the saturable absorption characteristic of the two‐dimensional GDY material, the pulsed Yb:SSO laser performances were investigated. The single pulse energy of 9.0 μJ and the peak power of 2.2 W were realized at an absorbed pump power of 3.151 W.

Compact Passively Q-Switched Ho:Sc2SiO5 Microchip Laser with a Few-Layer Molybdenum Disulfide Saturable Absorber

We present a passively Q-switched Ho:Sc2SiO5 microchip laser with a molybdenum disulfide saturable absorber for the first time. The molybdenum disulfide materials are fabricated on the end surface of a microchip Ho:SSO crystal. The physical length of the laser cavity is only 3 mm. Three output couplers with different transmissions are utilized to test the passively Q-switched laser performance. The maximum output power is 269.3 mW, under 4.1 W incident power, when the repetition rate is 112.8 kHz, this means that the single pulse energy is 2.39 μJ. The shortest pulsed time duration is 167.4 ns, corresponding to maximum peak power of 14.3 W. The M2 factor of the passively Q-switched microchip Ho:SSO laser is measured to be 1.17.

A passively Q-switched Ho:SSO laser with a Cr2+:ZnSe saturable absorber

Represented here is a continuous-wave (CW) operation laser and a passively Q-switch (PQS) Ho:SSO microchip laser with a Cr2+:ZnSe saturable absorber (SA). An end-pumped Tm:YAP laser pumping was employed, which operated at room temperature. Up to our knowledge, it is the first time to report a PQS microchip Ho:SSO laser. A maximum 418 mW CW laser output was realized with an absorbed pump power of 2.5 W. The slope efficiency was 59.4%. In the PQS mode, the maximum output power was 332 mW, at the same time the slope efficiency was down to 57.1%. The maximum repetition frequency was 0.69 kHz. The maximum pulse energy of 481 μJ was realized corresponding to the pulse width of 103 ns. The pulsed characteristics were studied in this work. The output wavelength for different modes were also investigated.

Electro-optically cavity-dumped Ho:SSO laser with a pulse width of 3.6 ns and linewidth of 70 pm

In this paper, we demonstrate an efficient cavity-dumped Ho:SSO laser linewidth-narrowed by a volume Bragg grating for the first time. When the incident pump power was 19.3 W, the maximum average output power of 6.33 W was achieved at a pulse repetition rate of 100 kHz, corresponding to the slope efficiency of 48.5% and optical conversion efficiency of 32.8%. The pulse width was kept at approximately 3.6 ns. The output wavelength was located at 2100.5 nm with a linewidth of 70 pm. In addition, the beam quality factor M2 of the cavity-dumped Ho:SSO laser at maximum output level was measured to be 1.5 by 90/10 knife-edge technology.

High power Ho:SSO laser resonantly pumped by a FBG-locked Tm fiber laser at 1940.3 nm

We demonstrate a high power continuous wave Ho:SSO laser resonantly pumped by a FBG-locked Tm fiber laser at 1940.3nm in this paper. The maximum output power of 8.72W was obtained under the incident pump power of 19.8W, corresponding to a slope efficiency of 54.3% and an optical conversion efficiency of 44.0%. The output wavelength of Ho:SSO laser was centered at 2113.5 nm. The Ho:SSO laser operated at TEM00 mode with a beam quality factor of Mx2 of 1.6 and My2 of 1.4 at maximum output level.

Efficient intracavity-pumped Ho:SSO laser with cascaded in-band pumping scheme

In this paper, we have demonstrated an efficient intra-cavity pumped Ho:SSO laser based on a cascaded in-band pumping scheme for the first time. The laser diode at 1.6 µm was used to pump the Tm:YAG crystal. At an incident LD pump power of 18.7 W, dual end-pumped Tm:YAG laser provides the maximum output power of 9.7 W with a slope efficiency of 55.9%. With the same incident LD power, a maximum output power of 4.9 W at 2116.5 nm was achieved with a slope efficiency of 31.6% in the Ho:SSO laser intra-cavity pumped by a Tm:YAG laser. The beam quality factor of the Ho:SSO laser at maximum output level was measured to be 1.1 and 1.2 in the horizontal and vertical directions, respectively.

Highly-Efficient Ho:SiSc2O5 Laser Pumped by a Narrow Line-Width Tm:YAP Laser at 1.94 μm

We present a highly-efficient continuous-wave Ho:SSO laser pumped by a diode-pumped Tm:YAP laser with a narrow linewidth (NL) of 0.3 nm. With the free-running (FR) Tm:YAP laser, we obtain a maximum output power of 2.23 W at an absorption pump power of 7.2 W, corresponding to an optical conversion efficiency of 31% and a slope efficiency of 42.6%. With the NL Tm:YAP laser, we obtain a maximum output power of 2.88 W at the same absorption pump power. The optical conversion efficiency increases to 40% when the slope efficiency increases to 55.5%. The output linewidth of the Ho:SSO laser is 0.8 nm when we use the Tm:YAP laser with a narrow linewidth of 1.8 nm pumped by a FR Tm:YAP laser. The beam quality also changes from 1.31 to 1.22.

A ps level actively mode-locked Ho:Sc2SiO5 laser at 2112.1 nm resonantly-pumped by Tm fiber laser

An actively mode-locked Ho:SSO laser was reported for the first time, which was resonantly-pumped by a Tm-doped fiber laser. Both performance of continuous wave (CW) mode and continuous wave mode-locked (CWML) were researched in this paper. For the CW mode, the maximum output power of the 2.88 W with the central wavelength of 2112.1 nm was achieved, when the absorbed pump power was 16.2 W. The optical-optical conversion efficiency was 17.8%. Compared with the CW mode, the maximum laser output power of CWML mode was a little lower, which was 2.72 W corresponding to an optical-optical conversion efficiency of 16.8%. However, the laser output wavelength of the CWML mode was the same as the CW mode focus on 2112.1 nm. The repetition rate of CWML pulse was measured to be 81.88 MHz with the single pulse energy of 33.2 nJ and pulse duration of 282.4 ps. The peak-power was 117.6 W.

Double Q-switch Ho:Sc2SiO5 laser by acousto-optic modulator combined with Cr2+:ZnSe saturable absorber

A double Q-switch (DQS) Ho:Sc2SiO5 laser modulated by a acousto-optic modulators (AOM) combined with a Cr2+:ZnSe saturable absorber (SA) was reported for the first time. The actively Q-switch (AQS) and passively Q-switch (PQS) were also studied. For the DQS mode, a maximum average output power of 2.49W under the incident pump power of 12.5W was obtained, corresponding to a slope efficiency of 24%. The characteristics of the DQS Ho:SSO laser versus different repetition frequencies (RF) of the AOM were researched. The maximum single-pulse energy of the DQS Ho:SSO laser was calculated to 1.98mJ. The maximum peak power of the DQS Ho:SSO laser was 49.5kW. The output beam quality factor M2 of DQS Ho:SSO laser was measured to be 1.15 with the highest peak power by knife-edge method at different positions.

Compact intra-cavity pumped low-threshold passively Q-switched Ho:Sc2SiO5 laser by a LD-pumped Tm:YAP laser at room temperature

A compact intra-cavity pumped low-threshold passively Q-switched (PQS) Ho:Sc2SiO5 (Ho:SSO) laser is reported for the first time. The Tm:YAlO3 (Tm:YAP) crystal and the Ho:SSO crystal are placed in the same laser cavity. A laser diode with a central wavelength of 793 nm is used to realize the output of the Ho:SSO laser. Both the continuous wave (CW) and PQS operation are investigated. A Cr2+:ZnSe is used as the saturable absorber in the PQS Ho:SSO laser. For the CW mode, the laser threshold is only 750 mW, which is 980 mW in the PQS mode. A maximum pulse energy of 699 µJ is primarily obtained, corresponding to the pulse width of 96 ns. The maximum repetition frequency is 1.46 kHz. The maximum pulse peak power can be calculated to be 7.28 kW. The beam quality factor M2 is calculated to be 1.4 with the maximum output power.

A continuous-wave wide-tunable Ho:Sc2SiO5 laser between 2.05 and 2.16 μm

A widely tunable Holmium-doped Sc2SiO5(SSO) 2 μm laser is reported in this manuscript, which has a wavelength tunable range of 110 nm (from 2050 to 2160 nm). A maximum output power of 3.02 W at 2111 nm is obtained when the laser operates on the continuous-wave free-running mode. A birefringent filter is used to realize the output wavelength tuning, which is put into the laser resonant cavity. The maximum output power of the tunable Ho:SSO laser is 2.07 W. It is the first time to report a widely tunable Ho:SSO laser. The wavelength tunable range is wider than the ones of other Ho-doped lasers and the output power is higher too, which could extend application fields of the Ho-doped lasers.

A Resonantly Pumped Single-Longitudinal Mode Ho:Sc2SiO5 Laser with Two Fabry–Perot Etalons

We present a single-longitudinal-mode Ho:Sc2SiO5 (Ho:SSO) laser pumped by a Tm:YAP laser for the first time. Two intra-cavity Fabry–Perot etalons were used to realize the single-longitudinal mode of operation. The maximum output power of 590 mW at 2111.91 nm was obtained with the incident power of 10.2 W, when the slope efficiency was 9.7% and the optical conversion efficiency was 5.8%. The M2 factor of the single longitudinal mode Ho:SSO laser was measured to be 1.17.

Passively Q-Switched Ho:SSO Laser by Use of a Cr2+:ZnSe Saturable Absorber**Supported by the National Natural Science Foundation of China under Grant No 61405046, and the Natural Science Foundation of Heilongjiang Province under Grant No 51305089.

A cw operation and a passively Q-switched (PQS) Ho:SSO laser (Cr2+:ZnSe as a saturable absorber) end-pumped by a Tm:YAP laser operating at near room temperature are reported. It is the first time to report a PQS Ho:SSO laser. For the cw mode, a maximum cw output power of 3.0 W is obtained, corresponding to a slope efficiency of 31.4%. For the PQS mode, a Cr2+:ZnSe is used as the saturable absorber, with transmission of 88.4% at 2112 nm. A maximum pulse energy of 1.29 mJ is obtained, corresponding to the pulse repetition frequency of 2.42 kHz. In this study, we change the distance between Cr2+:ZnSe and the output mirror to research the pulse characteristic of the PQS Ho:SSO laser. The minimum pulse width of 73.5 ns is obtained, corresponding to the pulse energy of 0.9 mJ and the pulse repetition frequency of 2.65 kHz.

Evaluation of the performance of a Ho: Sc2SiO5 laser pumped by a Tm:YAP laser

A continuous-wave 0.5 % Ho3+-doped Ho:Sc2SiO5 (Ho:SSO) laser output at 2112 nm pumped by a Tm:YAP laser is reported. The Ho:SSO bulk crystal was grown by the Czochralski technique. A maximum laser power of 3.72 W was obtained with a slope efficiency of 32.9%, when the transmittance of output mirror was 30%. In this experiment, two output mirrors with different transmittance were also researched. The output spectra of Ho:SSO laser with different output mirrors are also given. The M2 factor is found to be 1.29. In addition, the absorption and emission spectra are given in this paper.

端抽运准连续Yb∶SSO激光实验研究

端抽运准连续Yb∶SSO激光实验研究

A narrow linewidth continuous wave Ho:SSO laser with Fabry–Perot etalons

We report a narrow linewidth continuous wave Ho:SSO laser with Fabry–Perot etalons. The maximum output power reaches 2.35 W when the incident pump power is 15.5 W with the optical-to-optical conversion efficiency and slope efficiency 15.1 and 19.3 %, respectively. A stable output and a narrow linewidth less than 0.3 nm FWHM at 2112 nm are achieved. With the intra-cavity F–P etalons, the laser beam quality M2 = 1.26 ± 0.02, which is optimized obviously.

Performance of acousto-optically Q-switched Ho:SSO laser pumped by a Tm:YAP laser

Acousto-optically Q-switched operation of a Ho:SSO laser is reported for the first time. An average power of 2.23 W was obtained at a pulse repetition frequency from 5 to 20 kHz, with a corresponding to optical-to-optical conversion efficiency of 14.4% and a slope efficiency of 20%. The highest energy per pulse of 0.44 mJ in 28 ns was achieved at 2112 nm with a repetition rate of 5 kHz and peak power of 15 kW. The lifetime of Ho 3 + in the Sc 2 SiO 5 crystal host was also measured.

An acoustic-optically Q-switched Tm:SSO laser at 2 μm

An actively Q-switched Tm:SSO laser was realized by using an acoustic-optical (AO) modulator, and stable Q-switching operation was obtained with the pulse repetition frequency (PRF) varying from 1kHz to 10kHz. At PRF of 1kHz, the Tm:SSO laser yielded a shortest 308ns pulse with M2 factor less than 1.6 at 1968nm, corresponding to a single pulse energy of 128μJ and pulse peak power of 416W. The experimental results indicate the Tm:SSO crystal is favorable for obtaining low PRF 2μm laser pulses.

Study on characteristics of diode-pumped continuous-wave tunable and passively Q-switched Tm:SSO laser

In this paper, we present a diode-pumped continuous-wave tunable and Q-switched Tm:SSO laser with a semiconductor saturable absorber mirror. In continuous-wave regime, a maximum output power of 340 mW at 1,980.7 nm was obtained. With a quartz plate, wavelength-tunable continuous-wave operation was achieved from 1,922 to 2,020 nm. In Q-switched regime, a maximum output pulse energy of 14.7 μJ under a repetition rate of 800 Hz and a minimum pulse width of 7.6 μs corresponding to a repetition rate of 8.8 kHz around 1,974.4 nm were obtained from the passively Q-switched Tm:SSO laser.

Passive Q-switched mode locking of a diode-pumped Tm:SSO laser near 2 μm

With a fiber-coupled 790 nm laser diode array as the pump source and a 4 at.% Tm:Sc2SiO5 (Tm:SSO) crystal, laser action near 2 μm wavelength was successfully obtained with a compact four-mirror fold cavity. Using broadband carbon nanotube as the saturable absorber, a passively Q-switched mode-locked (QML) Tm:SSO laser is realized for the first time. 100% modulation depth of mode locking has been achieved. The duration of the mode-locked pulse is estimated to be about sub-100 ps with 92.6 MHz repetition rate within a Q-switched pulse envelope. The spectrum of the QML laser is centered at 1967.4 nm with a broad spectral region of ∼23 nm. A maximum average output power of 195 mW and Q-switched pulse energy of 4.7 μJ is obtained. The dependence of the operational parameters on pump power was also investigated experimentally.