M A M Salim

Using a black phosphorus saturable absorber to generate dual wavelengths in a Q-switched ytterbium-doped fiber laser

Using a few-layer black phosphorus (BP) thin film that acts as a saturable absorber (SA) in an ytterbium-doped fiber laser setup, we experimentally demonstrated a passively dual-wavelength Q-switching laser operation. The setup also incorporated a D-shaped polished fiber as a wavelength selective filter. As the SA was used in the ring cavity, a dual-wavelength Q-switch produced consistent outputs at 1038.68 and 1042.05 nm. A maximum pulse energy of 2.09 nJ with a shortest pulse width of 1.16 µs was measured for the achieved pulses. In addition, the repetition rate increased from 52.52 to 58.73 kHz with the increment of the pump level. Throughout the measurement process, the results were obtained consistently and this demonstrates that the BP film is a very good candidate to produce Q-switching pulses for the 1 micron region.

A black phosphorus-based tunable Q-switched ytterbium fiber laser

A compact, passively Q-switched fiber laser with a tunable output is demonstrated. The proposed system uses a short length ytterbium doped fiber to create a very stable and compact optical circuit that uses black phosphorus (BP) as a saturable absorber to generate the desired short pulses. A stable Q-switch pulse train is obtained, with an operational wavelength range from 1056.6-1083.3 nm. Concurrently, a maximum pulse energy and minimum pulse width as well as a repetition rate range of 7.1 nJ, 4 μs and 6.0-44.8 kHz respectively was obtained. The proposed system will be able to cater to a multitude of applications that require a compact yet robust and cost-effective pulse laser.

A passively Q-switched ytterbium-doped fiber laser based on a few-layer Bi2Se3 saturable absorber

In this work, we demonstrate a simple Q-switched pulsed ring ytterbium-doped fiber laser based on a few-layer TI:Bi2Se3 saturable absorber (SA). Few-layer bismuth selenide within a suspension was induced onto a fiber ferrule at room temperature via an optical deposition method, resulting in a simple SA for the laser. Stable Q-switched pulsed lasing was achieved at a low pump threshold of 122.2 mW at 974 nm. The pulse repetition rate ranged from 18.97 to 45.41 kHz, and the narrowest pulse width and the maximum pulse energy were 13.1 μs and 5.88 nJ respectively. Results indicated that TI:Bi2Se3 was also compatible with the 1 μm waveband, and hence could be considered a potential broadband SA for passively mode-locked and Q-switched optical fiber lasers.

Passively dual-wavelength Q-switched ytterbium doped fiber laser using Selenium Bismuth as saturable absorber

This paper describes a demonstration of a passively dual-wavelength Q-switched ytterbium-doped fiber laser using a selenium bismuth-based saturable absorber. By utilizing a short-length photonic crystal fiber in a ring cavity and performing adjustments to the polarization state of an incorporated polarization controller (PC), we obtained a stable dual-wavelength Q-switched output at 1037.14 and 1037.69 nm, with maximum pulse energy of 0.65 nJ, shortest pulse width of 8.46 μs, and pulse repetition rate from 15.37 to 59.24 kHz. The Q-switched laser output consistently achieved high-power stability with a 0.8 dB maximum fluctuation over a period of 20 min.

Highly stable and tunable narrow-spacing dual-wavelength ytterbium-doped fiber using a microfiber Mach–Zehnder interferometer

Abstract. We describe a successful demonstration of highly stable and narrowly spaced dual-wavelength output via an ytterbium-doped fiber laser. A microfiber-based Mach–Zehnder interferometer and a tunable bandpass filter were both placed into the laser ring cavity for the purpose of ensuring a stable and narrowly spaced dual-wavelength output. Experimental results comprised three sets of dual-wavelength lasing output with wavelength spacing of 0.06, 0.09, and 0.22 nm, respectively, and side-mode suppression ratio of ∼50  dBm. A subsequent stability test provided evidence that maximum power and wavelength fluctuation were less than 0.8 dB and 0.01 nm, respectively, and thus, the obtained output was considered to be highly stable in dual-wavelength operation. The proposed system offers advantages of flexibility in dual-wavelength laser generation in addition to excellent reliability.

The generation of passive dual wavelengths Q-switched YDFL by MoSe2film

A simple ytterbium doped fiber laser (YDFL) setup was used to generate Q-switching pulses by using a D-shaped polished fiber as a wavelength selective filter. The gain medium used in the cavity was ytterbium doped fiber with length 70 cm. By utilizing a MoSe2 film as saturable absorber into the cavity, a stable dual wavelength was produced at 1036.69 and 1039.22 nm. The wavelength separation of the output spectrum was 2.53 nm. We found a maximum pulse energy of 0.99 nJ and shortest pulse width of 1.2 µs. We have determined consistent dual-wavelength Q-switching pulses for the 1-micron region.

Generation of stable and narrow spacing dual-wavelength ytterbium-doped fiber laser using a photonic crystal fiber

Abstract We demonstrate the design and operation of novel narrow spacing and stable dual-wavelength fiber laser (DWFL). A 70-cm ytterbium-doped fiber has been chosen as the gain medium in a ring cavity arrangement. Our design includes a short length photonic crystal fiber, acting as a dual-wavelength stabilizer based on its birefringence coefficient and nonlinear behavior and tunable band pass filter (TBPF) to achieve narrow spacing spectrum lasing. Our laser output is considered to be highly stable, with power fluctuation less than 0.8 dB over a period of 15 min. The flexibility and tunability of TBPF, together with polarization controller enable the spacing tuning of the DWFL from 0.03 nm up to 0.07 nm for 1040 nm region, and 0.10 nm up to 0.40 nm for 1060 nm region. The tunable wavelength spacing shows the flexibility of the DWFL in addition to stable and reliable properties of fiber laser in 1-μm region.

Generation of an ultra-stable dual-wavelength ytterbium-doped fiber laser using a photonic crystal fiber

This paper describes the demonstration of a simple ytterbium-doped fiber (YDF) laser that utilized a short length of photonic crystal fiber (PCF) in a ring cavity and adjustments to the polarization state of an incorporated polarization controller (PC) to achieve a stable dual-wavelength output. The dual-wavelength lasing operation exploited the Mach-Zehnder interferometer effect, and the laser output consistently achieved high power stability with a 0.8 dB fluctuation over a period of 30 min. This proposed setup has the capability for adjustable spacing of two lasing wavelengths from a minimum of 0.40 nm to a maximum of 3.40 nm, allowing for flexibility in dual-wavelength laser generation in addition to stable and reliable system features.