Single-frequency Er Research Articles

High-Energy Injection-Seeded Single-Frequency Er:YAG Laser at 1645 nm Pumped by a 1532 nm Fiber Laser

A single-frequency, Q-switched Er:YAG laser, pumped by a 1532 nm fiber laser, has been demonstrated. At the pulse repetition frequency (PRF) of 200 Hz, the maximum single-frequency laser of 5.5 mJ is attained, and, correspondingly, the pulse width is 212 ns. Using the heterodyne technique, the single-frequency laser spectrum’s full width at half maximum is determined to be 2.73 MHz. The experimental results show that the single-frequency laser has excellent beam quality factors (M2) of 1.18 and 1.21.

Seed-injection Er:LuAG single-frequency, pulsed laser at 1650 nm

A 1650 nm seed-injection, single-frequency Er:LuAG pulsed laser with the double corner-cube-retroreflector (DCCR) structure has been demonstrated in this paper. In the total CCR structure (seed and slave laser), the maximum pulse energy of 2.15 mJ, with a pulse width of 225 ns under the pulse repetition frequency (PRF) of 200 Hz has been obtained, through the “ramp-hold-fire” injection-seeding technique. By utilizing the heterodyne technique, we have determined that the half-width pulse spectrum, which is 2.27 MHz. It is noteworthy that this marks the firstsuccessful realization of the 1650 nm single-frequency, Er:LuAG pulsed laser.

Demonstration on the performance enhancement of the 1.645 µm coherent Doppler lidar for long-range wind measurements with modification of laser transmitter and optical antenna

We have developed and experimentally investigated a long-range 1.645 µm coherent Doppler wind lidar (CDWL) system. A compact 1.645 µm single-frequency Er:YAG laser is utilized as the laser transmitter. The impact of laser transmitter parameters on wind detection was assessed using the figure of merit (FOM) concept. To enhance the measurement efficiency, the influence of wave aberrations on the heterodyne efficiency was analyzed. A Galilean telescope with an optical aperture of 100 mm is designed as the optical antenna based on the analysis. The line of sight (LOS) detection range exceeds 30.42 km with a data rate of 1 Hz at an elevation angle of 3.5°. To evaluate the effectiveness of the CDWL, comparison experiments were conducted between the 1.645 µm CDWL and a calibrated 1.55 µm CDWL, revealing a correlation coefficient of 0.9816 for the whole detection path in the wind velocity measurement.

All-solid-state 3-µm single-frequency Er:CaF2 laser with a stable and switchable wavelength.

We have demonstrated a 3-µm all-solid-state single-frequency laser with a stable center frequency and a switchable wavelength using the intra-cavity Fabry-Perot etalon method. Experimentally, the central wavelengths of the laser for the single-longitudinal mode are 2728 and 2794 nm, with maximum output powers of 268 and 440 mW, respectively. The corresponding single-longitudinal mode linewidths are 25 and 11 MHz. In particular, the central wavelengths of the single-longitudinal mode laser remain almost constant as the incident pump power increases. To the best of our knowledge, this study represents the first instance of using a laser diode to directly pump Er:CaF2 block single crystals for single-frequency lasers in the 3 µm region. Additionally, it achieves the highest output power of a 3-µm all-solid-state single-longitudinal mode.

45 W single frequency Er:Yb co-doped fiber amplifier at 1530 nm

A high-power continuous-wave single-frequency 1530 nm Er:Yb co-doped fiber amplifier is demonstrated with polarization-maintaining fiber as the gain medium. To achieve the greater than 50% population inversion required for efficient 1530 nm amplification, core pumping with a 1480 nm Raman fiber laser is utilized. The advantage of the 1480 nm core-pumping over the usual 9xx nm diode cladding pumping is proved by numerical simulation. The maximum single-frequency 1530 nm laser of 45.5 W with an amplified spontaneous emission suppression ratio of 46 dB is obtained at an incident 1480 nm laser of 60.7 W, corresponding to an optical efficiency of 74%. To date, this is the highest reported single-frequency 1530 nm laser, which will be used to pump an acetylene-filled hollow-core fiber laser.

Single-frequency Er:YAG ceramic pulsed laser with frequency stability close to 100 kHz

A single-frequency 1645 nm pulsed laser with frequency stability close to 100 kHz was demonstrated. The laser oscillator is injection-seeded by a single-frequency narrow linewidth Er:Y3Al5O12 (Er:YAG) nonplanar ring oscillator and frequency stabilized by the modified Pound–Drever–Hall method. The pulse repetition rate can be set from 100 to 500 Hz with the frequency stability from 82.72 kHz to 134.44 kHz and pulse energy from 9.84 mJ to 19.55 mJ. To our knowledge, this is the best frequency stability of a single-frequency pulsed laser with injection-seeding.

Single-frequency integrated laser on erbium-doped lithium niobate on insulator.

The erbium-doped lithium niobate on insulator (Er:LNOI) platform has great promise in the application of telecommunication, microwave photonics, and quantum photonics, due to its excellent electro-optic, piezo-electric, nonlinear nature, as well as the gain characteristics in the telecommunication C-band. Here, we report a single-frequency Er:LNOI integrated laser based on a dual-cavity structure. Facilitated by the Vernier effect and gain competition, the single-frequency laser can operate stably at 1531 nm wavelength with a 1484 nm pump laser. The output laser has a power of 0.31 µW, a linewidth of 1.2 MHz, and a side mode suppression ratio of 31 dB. Our work allows the direct integration of this laser source with existing LNOI components and paves the way for a fully integrated LNOI system.

Laser diode pumped high-energy single-frequency Er:YAG laser with hundreds of nanoseconds pulse duration

We demonstrated a high-energy single-frequency erbium-doped yttrium aluminum garnet (Er:YAG) laser. With 1470 nm laser diodes (LDs) as pumping sources, single-frequency laser pulses with energy of 28.6 mJ, 21.6 mJ, and 15.0 mJ are obtained at pulse repetition frequency of 200 Hz, 300 Hz, and 500 Hz, respectively. As far as we know, this is the highest single-frequency pulse energy with the Er:YAG gain medium. With the ring cavity design, pulse duration is maintained at hundreds of nanoseconds. This high-energy single-frequency laser with hundreds of nanoseconds pulse duration is a prospective laser source for light detection and ranging applications.

High-repetition rate, single-frequency laser with a double Er:YAG ceramics ring cavity.

A high pulse repetition frequency (PRF) single-frequency Er:YAG ceramic ring laser is demonstrated. A double-ceramics ring cavity both end-pumped by a 1532-nm fiber laser is also used to increase the pulse energy. The maximum single-frequency output energies are 21.0 mJ, 18.3 mJ, and 14.4 mJ at the PRF of 500 Hz, 750 Hz, and 1 kHz, respectively. Correspondingly, the pulse widths are 93.2 ns, 106.8 ns, and 130 ns. To the best of our knowledge, this is the highest energy at high PRFs obtained from a single-frequency injection-seeded Er:YAG ceramic laser.

半导体抽运的Er∶YAG陶瓷单频脉冲激光器

半导体抽运的Er∶YAG陶瓷单频脉冲激光器

Single-frequency, injection-seeded Er :YAG laser based on a bow-tie ring slave resonator

A diode pumped, injection-seeded -switched Er : YAG laser at is demonstrated. A single frequency Er : YAG monolithic nonplanar ring oscillator (NPRO) laser emitting at with a maximum output power of is used as a seed laser. The seed laser output is injected into a bow-tie slave laser, obtaining stable single-frequency -switched operation of the Er : YAG laser. The maximum single-frequency -switched Er : YAG laser output energy is at with a pulse duration of .

Single-frequency, Q -switched Er:YAG at room temperature injection-seeded by an Er:YAG nonplanar ring oscillator

We demonstrate a diode-pumped, injection-seeded Q-switched Er:YAG laser operating at room temperature. The diode-pumped single-frequency Er:YAG monolithic nonplanar ring oscillator (NPRO) was used as the seed laser emitting at 1645.22 nm with a maximum output power of 550 mW. Single-frequency, Q-switched operation of the Er:YAG laser was achieved by injection seeding. The output energy of the single-frequency Q-switched pulse was 3.5 mJ, with a pulse width of 195 ns at a repetition rate of 100 Hz.

A room temperature diode-pumped single frequency Er:YAG laser at 1645 nm

We report on p-polarized single-longitudinal-mode (SLM) operation of an Er:YAG laser at 1645.3 nm pumped by a laser diode at room temperature with three inserted Fabry–Perot etalons. An incident absorbed power of 6 W was used to generate the maximum single frequency output power of 75 mW. This stable SLM oscillation is encouraging since it may be used as a master laser for an injection-locked system.

A Resonantly Pumped 1645 nm Er:YAG Nonplanar Ring Oscillator With 10.5 W Single Frequency Output

We demonstrate a single frequency Er:YAG nonplanar ring oscillator (NPRO) resonantly pumped by a fiber laser. Up to 10.5 W single frequency laser output with a slope efficiency of 60.03% was achieved by optimizing the parameters of the Er:YAG NPRO. At 10.5 W output power the $M^{2}$ -factors of the Er:YAG NPRO were 1.09 and 1.24 in the $x$ - and $y$ - directions, respectively. The linewidth of the Er:YAG NPRO was 18.6 kHz.

400 mW low noise continuous-wave single-frequency Er,Yb:YAl_3(BO_3)_4 laser at 155 μm

We build up a LD end-pumped Er,Yb:YAB laser at 1.55 μm and improve the laser performance by end cooling the gain medium efficiently through a sapphire plate. 680 mW cw single transverse mode laser output was obtained with the slope efficiency of 16.3%. Using an etalon placed in the laser cavity, 400 mW cw single frequency 1.55 μm laser output was achieved with the slope efficiency of 11.8%. The laser power fluctuation was less than ± 1.3% in a given period of 1.5 hours. The 1.55 μm laser presents low noise properties, that the intensity and the phase noise reach the shot noise level for the analysis frequencies higher than 4 MHz and 5 MHz, respectively.

Resonantly pumped single frequency Er:YAG laser at 1645 nm

An efficient and single frequency Er:YAG laser pumped by an MGo:PPLN laser locked at 1532 nm with double F-P etalons was reported. The Er:YAG laser operated at 1645 nm, 550 mW of 1645 nm output was achieved under total incident pump power of 7 W. Using the etalons, 45 mW single frequency 1645.1 nm laser was achieved.

230-mW diode-pumped single-frequency Er:Yb laser at 1.5 μm

We report on a diode-pumped Er:Yb laser able to generate a single-frequency output power in excess of 200 mW at both 1.53 /spl mu/m and 1.56 /spl mu/m and over 300 mW in multimode operation. The tuning characteristics of the source are reported and discussed. The relative intensity noise presents in all configurations a peak value lower than -92 dB/Hz and its level decreases below -160 dB/Hz for frequencies higher than 8 MHz.

Single-frequency Er 3+ -doped silica-basedplanar waveguide laser withintegrated photo-imprinted Bragg reflectors

Single-longitudinal-mode operation of Er3+-P2O5-codoped silica planar waveguide lasers which are equipped with integrated Bragg grating reflectors is demonstrated, with a polarised output of 340 µW at 1546 nm. The gratings are photo-imprinted using 193 nm light exposure through a phase mask in GeO2-free optical waveguides that have been sensitised by H2 loading.