Continuous-wave singly resonant optical parametric oscillator placed inside a ring laser

A cw singly resonant optical parametric oscillator (SRO) was built and placed inside the cavity of a ring laser. The system consists of a diode-end-pumped Nd:YVO4 ring laser with intracavity periodically poled lithium niobate as the nonlinear gain medium of the SRO. When the laser was operated in a unidirectional mode, we obtained more than 520 mW of signal power in one beam. When the laser was operated in a bidirectional mode, we obtained 600 mW of signal power (300 mW in two separate beams). The power and the spectral features of the laser in the unidirectional and bidirectional modes were measured while the laser was coupled with the SRO. The results show that it is preferable to couple a SRO with a unidirectional ring laser.     

Diode-laser-pumped 1.328-mum Nd:Sr(5)(PO(4))(3) F laser and its intracavity frequency doubling

Nd:Sr(5) (PO(4))(3) F, known as Nd:S-FAP, is a new material for efficient, miniature diode-pumped solid-state lasers. By using a laser-diode pump operating at 805.4 nm, we successfully lased Nd:S-FAP at 1.328 mum. A slope efficiency of 33.5% and a laser threshold of 18.5 mW have been measured. By using KTP as an intracavity doubling crystal, we also achieved an intracavity frequency Nd:S-FAP laser at 0.664 mum with a threshold power of 18.2 mW, a TEM(00) mode red laser output power of 20.7 mW at 250 mW incident pump power corresponding to an optical efficiency of 8.3%. In addition, we discuss ways to improve efficiency by use of this material.     

Tunable green laser source based on frequency mixing of pump and laser radiation from a Nd:YVO4 crystal operating at 1342 nm with an intracavity KTP crystal

We report on cw tunable green laser light generation from a Nd:YVO4 laser operating at 1342 nm. Visible radiation was produced by a frequency mixing of pump and laser radiation inside an intracavity KTP crystal. When Nd:YVO4 was diode pumped, green laser was tunable from 503 to 505 nm. The green tuning range increases up to 22 nm when a Ti:sapphire laser is used as the pump source. In nonoptimal conditions, and for a pump power of 650 mW, green power was above 3 mW and close to 0.1 mW for Ti:sapphire and diode pumping, respectively.     

高效率低阈值激光材料Nd:S-FAP晶体

报道了一新型高效率,低阈值激光晶体Ｎｂ：Ｓ－ＦＡＰ的激光特性,利用染料激光和ＬＤ作为泵浦源,分别研究了Ｎｄ：Ｓ－ＦＡＰ晶体激光器的脉冲和连续输出的激光特性,染料激光泵浦Ｎｄ：Ｓ－ＦＡＰ激光器的泵浦阈值为２．５ｍＪ,     

Efficient Operation of an Intracavity-Doubled Nd:YVO(4)/KTP Laser End Pumped by a High-Brightness Laser Diode

Using a 1-W high-brightness laser diode as the pump source, we investigated the output characteristics of an intracavity frequency-doubled Nd:YVO(4)/KTP laser. Highly efficient operation was realized based on an optimized cavity design. The second-harmonic output power at 532 nm was measured to be 286.5 mW at an incident pump power of 881.4 mW, corresponding to an optical-to-optical efficiency of 32.5%.     

Generation of deep ultraviolet narrow linewidth laser by mixing frequency Ti:sapphire laser at 5 kHz repetition rate

We demonstrate a scheme to generate deep ultraviolet source by the single-stage high-power Ti:sapphire laser with linewidth of 0.05 nm cryogenically operating at repetition rate of 5 kHz. The fundamental laser was tuned by an intracavity birefringent filter and three etalons with an output power greater than 8 W, corresponding to about 17% optical efficiency. The pulse width was 112 ns and M2<1.1. By using the nonlinear crystals BiB3O6 and KBe2BO3F2, the output power of 2.2 W at second harmonic and 8.5 mW at fourth harmonic laser of about 195 nm were produced. This compact high-repetition rate laser with narrow linewidth would be a promising tunable source for spectroscopy.     

Unidirectional single-frequency operation of a Nd:YVO4 ring laser with and without a Faraday element

We demonstrate high-performance unidirectional and single-frequency ring-laser operation based on a diode-side-pumped Nd:YVO4 bounce amplifier, obtained in a ring system both with and without a Faraday rotating element. Ring-laser operation with intracavity Faraday unidirectional element produces 15-W cw output in a TEM00 and single-longitudinal mode with beam propagation parameter M2 < 1.1 with 35-W diode pumping. A novel non-Faraday-based ring laser uses a polarization-dependent output coupler and asymmetric polarization state in the birefringent Nd:YVO4 gain medium and is demonstrated to produce highly unidirectional (1200:1) single-frequency output of 14 W in a TEM00 mode with beam propagation factor M2 < 1.2 at 30 W of diode pumping.     

Laser-diode-pumped cw Nd:MgO:LiNbO(3) self-frequency-doubling laser around room temperature

A laser-diode-pumped cw self-frequency-doubling laser has been achieved in Nd:MgO:LiNbO3 crystal around room temperature. The second-harmonic output at λ = 547 nm to 8 mW was obtained with a miniature resonator in which only a crystal was included, without any extra intracavity component.     

Broadly tunable continuous-wave orange-red source based on intracavity-doubled Cr4+:forsterite laser

The operation of a room-temperature, continuous-wave, intracavity frequency-doubled Cr4+:forsterite laser capable of producing broadly tunable output in the orange-red region of the electromagnetic spectrum is described. Intracavity doubling was achieved in a periodically poled lithium niobate crystal that had gratings with different periods. Tunable second-harmonic output could be obtained between 613 and 655 nm. At a wavelength of 630 nm, intracavity doubling yielded as much as 45 mW of continuous-wave output. To the author's knowledge, this represents the highest second-harmonic-power generation obtained to date with a continuous-wave Cr4+:forsterite laser.     

Doppler-induced unidirectional operation of a continuous-wave Raman ring laser in H2

We demonstrate stable operation of a diode-pumped cw Raman ring laser in diatomic hydrogen gas. Doppler-induced asymmetry between the the forward and the backward Raman gains leads to inherent unidirectional operation in the forward direction without intracavity optical elements. Use of the ring-cavity geometry dilutes the deleterious effects of thermal lensing and significantly reduces optical feedback to the pump laser.     

Intracavity frequency-doubled and stabilized cw ring Nd:YAG laser with a pair of KTP crystals

Generation of an up to 1.5-W single-frequency and a 650-mW frequency-stabilized second harmonic at 1.06 μm has been demonstrated in a cw ring Nd:YAG laser with a pair of properly oriented KTP crystals in which the walk off between the intracavity modes has been eliminated. The frequency stability is better than 5 MHz for the second-harmonic output level of 650 mW. The fluctuation of power is less than 4%. PACS: 42.60. By. 42.65 Ky.     

Design and characterization of a diode-pumped, single longitudinal and transverse mode, intracavity-doubled cw Nd:YAG laser

We report on the experimental results of a diode-pumped, intracavity-doubled cw Nd:YAG laser, pumped by a 10-W fiber-coupled semiconductor laser at 808 nm and emitting as much as 600 mW in a stable single longitudinal mode and TEM(00) spatial mode. We discuss the main issues of the resonator design and the optimization of the intracavity second harmonic conversion by interpreting our results using simple models. Improvements for the current project are also discussed.     

Intracavity frequency doubling and Q switching in diode-laser-pumped Nd:YVO(4) lasers

A highly efficient and compact Nd:YVO(4) laser is proposed. In cw operation, a single-longitudinal-mode output of 95 mW and a multilongitudinal-mode output of 435 mW have been observed at 1.06 μm with a 1-W diode laser. Using a KTP crystal in the short laser cavity, a green output of 105 mW was generated. A Q-switched pulse with a peak power of 230 W and a pulse width of 8 ns was obtained with the intracavity KTP crystal, which was used as both an electro-optic Q switch and a frequency doubler.     

光纤饱和吸收体稳频窄线宽光纤激光器

结合光纤饱和吸收体与光纤光栅法布里-珀罗标准具,研制出了全光纤结构1550nm单频窄线宽掺铒光纤环形激光器.采用两个976nm激光二极管双向抽运作为抽运源,高掺杂浓度铒光纤作为增益介质,以行波腔消除空间烧孔效应,利用光纤光栅法布里-珀罗标准具窄带选模特性,以10m长低掺铒光纤饱和吸收体稳频,得到了十分稳定的窄线宽激光输出.激光器抽运阈值功率21mW,在抽运光功率为145mW时输出光功率39mW,斜率效率30%,信噪比大于50dB.采用延迟自外差方法精确测量光纤激光器线宽小于10kHz.     

Efficient upconversion-pumped continuous wave Er3+:LiLuF4 lasers

We report on detailed spectroscopic investigations and efficient visible upconversion laser operation of Er³⁺:LiLuF₄. This material allows for efficient resonant excited-state-absorption (ESA) pumping at 974 nm. Under spectroscopic conditions without external feedback, ESA at the laser wavelength of 552 nm prevails stimulated emission. Under lasing conditions in a resonant cavity, the high intracavity photon density bleaches the ESA at 552 nm, allowing for efficient cw laser operation.We obtained the highest output power of any room-temperature crystalline upconversion laser. The laser achieves a cw output power of 774 mW at a slope efficiency of 19% with respect to the incident pump power delivered by an optically-pumped semiconductor laser. The absorption efficiency of the pump radiation is estimated to be below 50%.To exploit the high confinement in waveguides for this laser, we employed femtosecond-laser pulses to inscribe a cladding of parallel tracks of modified material into Er³⁺:LiLuF₄ crystals. The core material allows for low-loss waveguiding at pump and laser wavelengths. Under Ti:sapphire pumping at 974 nm, the first crystalline upconversion waveguide laser has been realized. We obtained waveguide-laser operation with up to 10 mW of output power at 553 nm.     

A Diode-laser-bar Pumped Stable CW Nd: YAG Slab Laser and its Frequency Doubling

Abstract

A high power Nd: YAG mini-slab laser transversely pumped by two diode laser arrays has been investigated. The simplicity and compactness of this pumping scheme provides intrinsic stability in both the output power and the beam pointing. A linearly polarized TEM₀₀ mode output power of 3·6 W at 1064 nm was achieved with a linear cavity, and 1 W of single frequency green light at 532 nm was generated by intracavity doubling in a ring cavity.     

High-powered green light generation by intracavity frequency doubling using grating feedback optics

Grating feedback optics is shown to contribute to narrowing the spectral bandwidth of a multilongitudinal-mode laser diode to less than 0.2 nm and tuning the lasing wavelength to the peak absorption wavelength of Nd:YVO(4). A continuous green light of 31 mW was efficiently generated by intracavity frequency doubling of the Nd:YVO(4) laser with a KTiOPO(4) crystal. A relative intensity noise of less than -140 dB/Hz was obtained in the frequency region greater than 2 MHz. The noise characteristics of generated green light are discussed as compared with the case of using a single-longitudinal-mode laser diode as the pumping source.     

Unidirectional single-mode Nd:YAG laser with a planar semimonolithic ring cavity

Unidirectional single-mode operation of a diode-pumped Nd:YAG laser with a planar semimonolithic ring cavity has been demonstrated at 1064 nm. The semimonolithic cavity consists of a laser active medium placed in a magnetic field, a crystal quartz plate, and an output coupling mirror, which form an optical diode by acting as a Faraday rotator, a reciprocal polarization rotator, and a partial polarizer, respectively. A single-mode output power of 155 mW and a slope efficiency of 17% were obtained with a 1.2-W diode laser at 809 nm. A laser linewidth of less than 100 kHz is inferred from a beat note frequency spectrum between two identical laser systems and continuous tuning to greater than 2 GHz was observed.     

163 fs被动锁模掺Er~(3+)光纤激光器

研制了一种采用非线性偏振旋转锁模效应的被动锁模掺Er3+飞秒激光器。利用性能稳定的980 nm激光二极管(LD)作为抽运光源,以高掺杂Er3+光纤为增益介质,在抽运功率为650 m W时,激光器锁模输出重复频率为31.25 MHz、平均输出功率为70 m W、中心波长为1565 nm、光脉冲宽度为163 fs的稳定飞秒脉冲激光。该激光器易于操作和调节,并且锁模状态稳定可以长时间的运行,其光纤结构更有利于小型化和便携化。     

Efficient operation of a diode-bar-pumped Nd:YAG laser on the low-gain 1123-nm line

Efficient operation of a Nd:YAG laser on the low-gain 1123-nm transition by end pumping with the reshaped output from a 7-W diode bar is reported. Using a simple standing-wave laser configuration and pumping with 5.6 W of incident power yielded a laser output power of 1.7 W in a near-diffraction-limited TEM00 mode with a beam quality factor of M2 < or approximately equal to 1.1. A unidirectional single-frequency ring laser was also constructed, yielding 180 mW of single-frequency output. The prospects for further increase in power by optimization of the resonator design are discussed.