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11 pages, 3520 KiB

Open AccessCommunication

Diode-End-Pumped Continuous-Wave Tunable Nd³⁺:LiYF₄ Laser Operating on the ⁴F_3/2→⁴I_13/2 Transition

by Chu Chu, Shuang Wang, Xinhua Fu and Zhenhua Du

Photonics 2025, 12(6), 613; https://doi.org/10.3390/photonics12060613 - 14 Jun 2025

Viewed by 302

A laser diode (LD) end-pumped continuous-wave (CW) tunable Nd³⁺:LiYF₄ (Nd:YLF) laser operating on the ⁴F_3/2→⁴I_13/2 transition was performed. Four single-wavelength (SW) lasing at 1321, 1314, 1371, and 1364 nm in the π-polarized direction and [...] Read more.

A laser diode (LD) end-pumped continuous-wave (CW) tunable Nd³⁺:LiYF₄ (Nd:YLF) laser operating on the ⁴F_3/2→⁴I_13/2 transition was performed. Four single-wavelength (SW) lasing at 1321, 1314, 1371, and 1364 nm in the π-polarized direction and three SW lasing at 1314, 1326, and 1371 nm in the σ-polarized direction were achieved using a tuning prism. At 20 W pump power, the σ-polarized 1314 nm emission generated 7.3 W power output with 39.4% slope efficiency. Further, the three-pair of switchable π-polarized dual-wavelengths (DWs) at 1321/1314 nm, 1371/1364 nm, and 1321/1364 nm and the two-pair of switchable σ-polarized DWs at 1314/1326 nm and 1314/1371 nm were also realized by rotating an intracavity birefringence filter (BF). In addition, by employing dual intracavity BFs, the balanced DW output power was attained, achieving 6.4 W total maximum output at 1314/1321 nm in the π-polarized direction. Full article

(This article belongs to the Section Lasers, Light Sources and Sensors)

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12 pages, 4832 KiB

Open AccessArticle

Dual Interferometric Interrogation for DFB Laser-Based Acoustic Sensing

by Mehmet Ziya Keskin, Abdulkadir Yentur and Ibrahim Ozdur

Sensors 2025, 25(9), 2873; https://doi.org/10.3390/s25092873 - 2 May 2025

Viewed by 522

Abstract

Acoustic sensing has many applications in engineering, one of which is fiber-optic hydrophones (FOHs). Conventional piezoelectric hydrophones face limitations related to size, electromagnetic interference, corrosion, and narrow operating bandwidth. Fiber-optic hydrophones, particularly those employing distributed feedback (DFB) lasers, offer a compelling alternative due [...] Read more.

Acoustic sensing has many applications in engineering, one of which is fiber-optic hydrophones (FOHs). Conventional piezoelectric hydrophones face limitations related to size, electromagnetic interference, corrosion, and narrow operating bandwidth. Fiber-optic hydrophones, particularly those employing distributed feedback (DFB) lasers, offer a compelling alternative due to their mechanical flexibility, resistance to harsh conditions, and broad detection range. DFB lasers are highly sensitive to external perturbations such as temperature and strain, enabling the precise detection of underwater acoustic signals by monitoring the resultant shifts in lasing wavelength. This paper presents an enhanced interrogation mechanism that leverages Mach–Zehnder interferometers to translate wavelength shifts into measurable phase deviations, thereby providing cost-effective and high-resolution phase-based measurements. A dual interferometric setup is integrated with a standard demodulation algorithm to extend the dynamic range of these sensing systems. The experimental results demonstrate a substantial improvement in performance, with the dynamic range increasing from 125 dB to 139 dB at 1 kHz without degrading the noise floor. This enhancement significantly expands the utility of FOH-based systems in underwater environments, supporting applications such as underwater surveillance, submarine communication, and marine ecosystem monitoring. Full article

(This article belongs to the Section Optical Sensors)

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15 pages, 3122 KiB

Open AccessArticle

Strain-Compensated Quantum Well Asymmetric Waveguide Edge-Emitting Laser Operating at 730 nm

by Lutai Fan, Lijie Cao, Peng Jia, Qian Liu, Baiheng Liu, Haofei Chen, Yongyi Chen, Li Qin, Lei Liang, Yuxin Lei, Cheng Qiu, Yue Song, Yubing Wang, Yongqiang Ning and Lijun Wang

Sensors 2025, 25(4), 1173; https://doi.org/10.3390/s25041173 - 14 Feb 2025

Viewed by 764

Abstract

Semiconductor lasers operating at the 730 nm peak wavelength have diverse applications, including biomedical diagnostics, agricultural lighting, and high-precision sensing. However, quantum well (QW) materials, commonly employed at this wavelength, often fail to simultaneously meet the dual requirements of lattice matching and bandgap [...] Read more.

Semiconductor lasers operating at the 730 nm peak wavelength have diverse applications, including biomedical diagnostics, agricultural lighting, and high-precision sensing. However, quantum well (QW) materials, commonly employed at this wavelength, often fail to simultaneously meet the dual requirements of lattice matching and bandgap alignment. In this study, GaAsP/AlGaInP large strain compensation QW with lattice mismatches of −7.533‰ and 1.112‰ was developed. Strain compensation was utilized to address the lattice mismatch while ensuring lasing action at 730 nm. Based on this, the impact of waveguide design, particularly graded and asymmetric waveguides, on the power output was explored. Additionally, the relationship between the doping profile of the device and lasing efficiency was investigated. The completed 100 μm wide semiconductor edge-emitting laser (EEL) achieved 730 nm continuous wave laser with 1 W output power at 2 A current. This study proposes an approach to enhance the lasing power and optoelectronic conversion efficiency of lasers and provide valuable solutions for their practical applications. Full article

(This article belongs to the Section Optical Sensors)

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16 pages, 10770 KiB

Open AccessArticle

A Tunable and Switchable Multi-Wavelength Erbium-Doped Fiber Laser Based on a Curvature Mach–Zehnder Interferometer Filter Using Thin-Core Fiber

by Christian Perezcampos-Mayoral, Jaime Gutiérrez-Gutiérrez, José Luis Cano-Pérez, Marciano Vargas-Treviño, Lorenzo Tepech-Carrillo, Erick Israel Guerra-Hernández, Itandehui Belem Gallegos-Velasco, Pedro Antonio Hernández-Cruz, Eeduardo Pérez-Campos-Mayoral, Victor Hugo Ojeda-Meixueiro, Julián Moisés Estudillo-Ayala, Juan Manuel Sierra-Hernandez and Roberto Rojas-Laguna

Appl. Sci. 2024, 14(24), 11578; https://doi.org/10.3390/app142411578 - 11 Dec 2024

Cited by 2 | Viewed by 1250

Abstract

We propose and demonstrate a tunable and switchable multi-wavelength fiber ring laser configuration based on a Mach–Zehnder interferometer (MZI) filter. The MZI was fabricated using a core-offset splicing technique, with a 2 cm piece of thin-core erbium-doped fiber (TCEDF), with a core diameter [...] Read more.

We propose and demonstrate a tunable and switchable multi-wavelength fiber ring laser configuration based on a Mach–Zehnder interferometer (MZI) filter. The MZI was fabricated using a core-offset splicing technique, with a 2 cm piece of thin-core erbium-doped fiber (TCEDF), with a core diameter of 2.90 µm, coupled in the central region of the MZI between two segments of single-mode fiber (SMF). By applying curvature to the MZI filter, we generated lasing single-, double-, triple-, and quadruple-emission lines with a curvature range from 2.3452 m⁻¹ to 6.0495 m⁻¹. A single-emission lasing line can be tuned from 1556.63 nm to 1564.25 nm with a tuning span of 7.62 nm and an SMSR of 49.80 dB. The laser emission can be switched to quadruple- and triple-emission lasing signals, with SMSR values of 39.96 dB and 36.83 dB, respectively. The dual-narrow emission lasing signal can be tuned from 1564.56 nm to 1561.34 nm, with an SMSR of 40.46 dB. Another lasing dual-emission signal can be tuned from 1585.69 nm to 1576.89 nm, producing an 8.8 nm tuning range, and from 1572.53 nm to 1563.66 nm, producing an 8.87 nm range, with the best SMSR of 42.35 dB. Full article

(This article belongs to the Special Issue Recent Trends in Fiber Optic Sensor: Technology and Applications)

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16 pages, 16410 KiB

Open AccessArticle

A Tunable and Switchable Multi-Wavelength Erbium-Doped Fiber Ring Laser Enabled by Adjusting the Spectral Fringe Visibility of a Mach-Zehnder Fiber Interferometer

by Romeo Emmanuel Nuñez Gomez, Gilberto Anzueto Sánchez, Alejando Martínez Ríos, Ariel Fong González, Alfredo Olarte Paredes, Areli Marlen Salgado Delgado, Jesús Castrellón Uribe and René Salgado Delgado

Appl. Sci. 2024, 14(21), 9846; https://doi.org/10.3390/app14219846 - 28 Oct 2024

Cited by 3 | Viewed by 2407

Abstract

This paper presents a tunable, switchable multi-wavelength emission from an erbium-doped fiber ring laser, enabled by adjusting the spectral fringe visibility of a fiber interferometer filter. The filter is formed with specially designed concatenated tapered fibers to configure a Mach-Zehnder fiber interferometer (MZFI). [...] Read more.

This paper presents a tunable, switchable multi-wavelength emission from an erbium-doped fiber ring laser, enabled by adjusting the spectral fringe visibility of a fiber interferometer filter. The filter is formed with specially designed concatenated tapered fibers to configure a Mach-Zehnder fiber interferometer (MZFI). The laser emission is highly flexible and reconfigurable, allowing for tuning between single- and dual-wavelength operation. The laser can switch sequentially from one up to six wavelengths by fixing the curvature and adjusting the polarization state. The lasing emission is generated over a stable wavelength range between 1559.59 nm and 1563.54 nm, exhibiting an optical signal-to-noise ratio (OSNR) exceeding ~35 dB. The performance of amplitude and wavelength fluctuations were evaluated, indicating an appropriate stability of ~3 dB and a shift less than 0.1 nm within a 45 min period at room temperature. A detailed comparison with the literature is given. Full article

(This article belongs to the Special Issue Recent Trends in Fiber Optic Sensor: Technology and Applications)

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15 pages, 8067 KiB

Open AccessArticle

Research on an Enhanced Detuned-Loading Effect in Integrated Two-Section DFB Lasers with High Modulation Bandwidths

by Yunshan Zhang, Hongming Gu, Guolong Ma, Shijian Guan, Tao Fang and Xiangfei Chen

Micromachines 2023, 14(11), 1994; https://doi.org/10.3390/mi14111994 - 27 Oct 2023

Viewed by 1993

Abstract

A novel high-speed directly modulated two-section distributed-feedback (TS-DFB) semiconductor laser based on the detuned-loading effect is proposed and simulated. A grating structure is designed by the reconstruction-equivalent-chirp (REC) technique. A π phase shift is introduced into the reflection grating, which can provide a [...] Read more.

A novel high-speed directly modulated two-section distributed-feedback (TS-DFB) semiconductor laser based on the detuned-loading effect is proposed and simulated. A grating structure is designed by the reconstruction-equivalent-chirp (REC) technique. A π phase shift is introduced into the reflection grating, which can provide a narrow-band reflection region with a sharp falling slope on both sides of the reflection spectrum, thus enhancing the detuned-loading effect. Owing to its unique dual-falling-edges structure, the bandwidth can be improved even when the lasing wavelength shifts beyond the left falling edge due to a thermal effect in the actual test, in which condition the detuned-loading effect can be used twice, which greatly improves the yield. The modulation bandwidth is increased from 17.5 GHz for a single DFB laser to around 24 GHz when the lasing wavelength is located on the left falling edge of the TS-DFB laser based on the detuned-loading effect, and it can be increased to 22 GHz for the right side. An eight-channel laser array with precise wavelength spacing is investigated, with a side-mode suppression ratio (SMSR) >36 dB. In addition, TS-DFB lasers with uniform reflection gratings are studied, and simulated results show that the modulation characteristic is far inferior to the laser with a phase-shifted grating reflector. Full article

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15 pages, 4716 KiB

Open AccessArticle

Active Differential Fiber Coupled Plasmon Waveguide Resonance Sensor Based on the Mode Competition Effect

by Songquan Li, Qian Yang, Laixu Gao, Miao Zhu and Changwei Zou

Photonics 2023, 10(10), 1141; https://doi.org/10.3390/photonics10101141 - 11 Oct 2023

Viewed by 1207

Abstract

We proposed an active differential intensity (DI) fiber coupled plasmon waveguide resonance (CPWR) sensor based on the mode competition effect in the C-band, aiming to enhance the sensitivity. The sensing head is a fiber probe with a sensing layer of ITO/Au/ITO/TiO₂ film, [...] Read more.

We proposed an active differential intensity (DI) fiber coupled plasmon waveguide resonance (CPWR) sensor based on the mode competition effect in the C-band, aiming to enhance the sensitivity. The sensing head is a fiber probe with a sensing layer of ITO/Au/ITO/TiO₂ film, enabling the excitation of CPWR in the C-band. The narrow CPWR spectrum allows DI interrogation by tracking the intensity of light at two wavelengths. The fiber probe is inserted into a dual-wavelength fiber laser to adjust the intra-cavity loss at the two lasing wavelengths. By using the differential modulation of the reflectivity from the refractive index variations, the mode competition effect is triggered. The powers at two lasing wavelengths change oppositely, enlarging the power difference and then resulting in enhanced sensitivity. The average sensitivity is up to 5702 dB/RIUs, which is 10 times higher than that of conventional DI interrogation. The sensitivity enhancement mechanism based on the mode competition effect provides a new technical approach for enhancing the sensitivity of DI SPR sensors. Full article

(This article belongs to the Special Issue Advances in Photonic Materials and Technologies)

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11 pages, 2707 KiB

Open AccessArticle

Numerical Analysis of Dual-Wavelength Tungsten-Tellurite Fiber Raman Lasers with Controllable Mode Switching

by Elena A. Anashkina and Alexey V. Andrianov

Fibers 2023, 11(10), 84; https://doi.org/10.3390/fib11100084 - 10 Oct 2023

Cited by 2 | Viewed by 1854

Abstract

Fiber laser sources in the spectral range near 1.7–1.8 μm are in highly demand for a lot of applications. We propose and theoretically investigate a dual-wavelength switchable Raman tungsten-tellurite fiber laser in the 1.7–1.8 µm range which can produce two stable modes at [...] Read more.

Fiber laser sources in the spectral range near 1.7–1.8 μm are in highly demand for a lot of applications. We propose and theoretically investigate a dual-wavelength switchable Raman tungsten-tellurite fiber laser in the 1.7–1.8 µm range which can produce two stable modes at frequencies separated by ~7 THz with a pump at 1.55 µm. The Raman waves shifted by 19.8 THz (mode 1) and 27.5 THz (mode 2) from the pump frequency can be generated near two different maxima of the Raman gain spectrum (gain is higher at 19.8 THz and twice lower at 27.5 THz). We numerically simulate two-mode Raman lasing with allowance for energy transfer from the pump wave to modes 1 and 2, and from mode 1 to mode 2 due to inelastic Raman scattering. Diagrams of generation regimes depending on system parameters are constructed. We demonstrate controlled switching between two modes by changing the pump power. For the same intracavity losses for both Raman modes at relatively low pump powers, only mode 1 is generated. At medium pump power, generation occurs simultaneously in both modes. At relatively high pump power, only mode 2 is generated near the weaker maximum. This effect seems surprising, but a rigorous explanation with allowance for the nonlinear interaction between mode 1 and mode 2 is found. When losses for one of the modes change, switching of the generated regimes is also predicted. Full article

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13 pages, 7077 KiB

Open AccessArticle

Wavelength-Tunable Single-Longitudinal-Mode Narrow-Linewidth Thulium/Holmium Co-Doped Fiber Laser with Phase-Shifted Fiber Bragg Grating and Dual-Coupler-Ring Filter

by Dongyuan Li, Ting Feng, Shaoheng Guo, Shengbao Wu, Fengping Yan, Qi Li and Xiaotian Steve Yao

Photonics 2023, 10(6), 693; https://doi.org/10.3390/photonics10060693 - 19 Jun 2023

Cited by 3 | Viewed by 2327

Abstract

A wavelength-tunable single-longitudinal-mode (SLM) narrow-linewidth thulium/holmium co-doped fiber laser (THDFL) was developed in this study. The lasing wavelength was determined by combining a phase-shifted fiber Bragg grating (PS-FBG) and a uniform FBG (UFBG). SLM oscillation was achieved by incorporating a dual-coupler ring filter [...] Read more.

A wavelength-tunable single-longitudinal-mode (SLM) narrow-linewidth thulium/holmium co-doped fiber laser (THDFL) was developed in this study. The lasing wavelength was determined by combining a phase-shifted fiber Bragg grating (PS-FBG) and a uniform FBG (UFBG). SLM oscillation was achieved by incorporating a dual-coupler ring filter with the PS-FBG. At a pump power of 2.0 W, the THDFL exhibited excellent SLM lasing performance with a stable optical spectrum. It operated at an output wavelength of ~2050 nm with an optical signal-to-noise ratio of >81 dB, an output power fluctuation of 0.15 dB, a linewidth of 8.468 kHz, a relative intensity noise of ≤−140.32 dB/Hz@≥5 MHz, a slope efficiency of 2.15%, and a threshold power of 436 mW. The lasing wavelength tunability was validated experimentally by stretching the PS-FBG and UFBG simultaneously. The proposed THDFL had significant potential for application in many fields, including free-space optical communication, LiDAR, and high-precision spectral measurement. Full article

(This article belongs to the Special Issue Single Frequency Fiber Lasers and Their Applications)

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12 pages, 5204 KiB

Open AccessCommunication

1064/1319 nm Dual-Wavelength Alternating Electro-Optic Q-Switched Laser Based on the Common Q-Switching Bias Voltage

by Jingdong Sun, Chunhe Yu, Yuan Dong, Chunting Wu and Guangyong Jin

Photonics 2023, 10(6), 609; https://doi.org/10.3390/photonics10060609 - 24 May 2023

Cited by 2 | Viewed by 2005

Abstract

A dual-wavelength alternating electro-optic (EO) Q-switched laser operating at 1064 and 1319 nm is designed, which takes the structure of double the gain crystals and a single EO modulator with the common Q-switching bias voltage (CQBV). The output characteristics of alternating dual-wavelength pulse [...] Read more.

A dual-wavelength alternating electro-optic (EO) Q-switched laser operating at 1064 and 1319 nm is designed, which takes the structure of double the gain crystals and a single EO modulator with the common Q-switching bias voltage (CQBV). The output characteristics of alternating dual-wavelength pulse lasers are studied via simulations and experiments. The results show that the energy ratio of the two lasing wavelengths can be controlled by changing the CQBV. This is because the CQBV affects the loss of two resonators, 1064 and 1319 nm, at the same time. The gain–loss relationship in the dual-wavelength laser resonators can be controlled by changing the CQBV in a certain range. Full article

(This article belongs to the Topic Applications of Photonics, Laser, Plasma and Radiation Physics)

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12 pages, 3501 KiB

Open AccessArticle

Dual-Wavelength Lasing with Orthogonal Circular Polarizations Generated in a Single Layer of a Polymer–Cholesteric Liquid Crystal Superstructure

by Donghao Yang, Marouen Chemingui, Yu Wang, Xinzheng Zhang, Irena Drevensek-Olenik, Faheem Hassan, Qiang Wu, Yigang Li, Lotfi Saadaoui and Jingjun Xu

Polymers 2023, 15(5), 1226; https://doi.org/10.3390/polym15051226 - 28 Feb 2023

Cited by 6 | Viewed by 3707

Abstract

We investigate the laser emission from a polymer–cholesteric liquid crystal superstructure with coexisting opposite chiralities fabricated by refilling a right-handed polymeric scaffold with a left-handed cholesteric liquid crystalline material. The superstructure exhibits two photonic band gaps corresponding to the right- and left-circularly polarized [...] Read more.

We investigate the laser emission from a polymer–cholesteric liquid crystal superstructure with coexisting opposite chiralities fabricated by refilling a right-handed polymeric scaffold with a left-handed cholesteric liquid crystalline material. The superstructure exhibits two photonic band gaps corresponding to the right- and left-circularly polarized light. By adding a suitable dye, dual-wavelength lasing with orthogonal circular polarizations is realized in this single-layer structure. The wavelength of the left-circularly polarized laser emission is thermally tunable, while the wavelength of the right-circularly polarized emission is relatively stable. Due to its relative simplicity and tunability characteristics, our design might have broad application prospects in various fields of photonics and display technology. Full article

(This article belongs to the Special Issue Mechanical and Structure–Property Relationships of Polymer Composites)

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12 pages, 5009 KiB

Open AccessArticle

Active Compensation of Differential Group Delay in a Dual-Wavelength Pulsed Fiber Laser Driven by Quasi-Synchronous Pumping

by Boris Nyushkov, Aleksey Ivanenko, Gleb Vishnyakov, Alexey Kharauzov and Sergey Smirnov

Photonics 2023, 10(1), 42; https://doi.org/10.3390/photonics10010042 - 31 Dec 2022

Cited by 1 | Viewed by 1997

Abstract

We report on synchronized dual-wavelength (1.07 μm and 1.24 μm) pulsed lasing driven by a quasi-synchronous primary pumping (at 0.98 μm) of an Yb-doped fiber laser, which incorporates also a P₂O₅-doped fiber as an intracavity Raman converter. The original [...] Read more.

We report on synchronized dual-wavelength (1.07 μm and 1.24 μm) pulsed lasing driven by a quasi-synchronous primary pumping (at 0.98 μm) of an Yb-doped fiber laser, which incorporates also a P₂O₅-doped fiber as an intracavity Raman converter. The original method developed for such lasing does not require saturable absorbers (or optical modulators) and dispersion management. We demonstrated that the mechanism of the quasi-synchronous pumping enables the aforesaid stationary lasing in spite of significant differential group delay (DGD) inevitably acquired by light pulses with such different wavelengths during an intracavity round trip due to large normal chromatic dispersion. This DGD can be actively compensated at every round trip by the forced “acceleration” of the pulses at 1.07 μm in the Yb-doped active fiber due to the overrated frequency of the quasi-synchronous pumping at 0.98 μm. This mechanism is related to the particular pulse amplification dynamics in a such gain-modulated active fiber. The demonstrated approach to synchronized dual-wavelength pulsed lasing in a single-cavity fiber laser features remarkable simplicity and reliability. Our proof-of-concept setup enabled the stable two-wavelength generation of regular trains of nanosecond pulses with energy up to 34 nJ at equal repetition rates. Full article

(This article belongs to the Section Lasers, Light Sources and Sensors)

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12 pages, 24525 KiB

Open AccessCommunication

Eight-Wavelength-Switchable Narrow Linewidth Erbium-Doped Fiber Laser Based on Cascaded Superimposed High-Birefringence Fiber Bragg Grating

by Dongyuan Li, Ting Feng, Weiwei Sun, Shengbao Wu, Fengping Yan, Qi Li and Xiaotian Steve Yao

Electronics 2022, 11(22), 3688; https://doi.org/10.3390/electronics11223688 - 10 Nov 2022

Cited by 7 | Viewed by 2208

Abstract

A narrow-linewidth eight-wavelength-switchable erbium-doped fiber laser is proposed, and its performance is demonstrated. A cascaded superimposed high-birefringence fiber Bragg grating is used to determine the lasing wavelengths. The combination of a Fabry–Pérot filter and a single-coupler ring is adopted to achieve the single-longitudinal-mode [...] Read more.

A narrow-linewidth eight-wavelength-switchable erbium-doped fiber laser is proposed, and its performance is demonstrated. A cascaded superimposed high-birefringence fiber Bragg grating is used to determine the lasing wavelengths. The combination of a Fabry–Pérot filter and a single-coupler ring is adopted to achieve the single-longitudinal-mode (SLM) oscillation. By introducing the enhanced polarization-hole-burning effect to suppress the gain competition between different wavelength lasers, the stable lasing output is guaranteed. When the pump power is 200 mW, by adjusting the polarization controller to balance the gain and loss in the laser cavity, 24 switchable lasing modes are achieved, including 8 single-wavelength operations and 16 dual-wavelength operations with orthogonal polarization states. For single-wavelength operations, every laser is in the SLM lasing state, with a high stabilized optical spectrum, a linewidth of approximately 1 kHz, an optical signal-to-noise ratio (OSNR) as high as 73 dB, a relative intensity noise of less than −150 dB/Hz, and very good polarization characteristics. For dual-wavelength operations, the lasers also have a stable spectrum and an OSNR as high as 65 dB. The proposed fiber laser has a wide range of applications, including long-haul coherence optical communication, optical fiber sensing, and dense wavelength-division-multiplexing. Full article

(This article belongs to the Special Issue Optical Fiber Communications: Innovations and Challenges)

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14 pages, 4039 KiB

Open AccessArticle

Tunable and Switchable Dual-Wavelength SLM Narrow-Linewidth Fiber Laser with a PMFBG-FP Filter Cascaded by Multi-Ring Cavity

by Mingquan Gao, Bin Yin, Yanzhi Lv, Guofeng Sang, Benran Hou, Haisu Li, Muguang Wang and Songhua Wu

Photonics 2022, 9(10), 756; https://doi.org/10.3390/photonics9100756 - 12 Oct 2022

Cited by 19 | Viewed by 2859

Abstract

A single longitudinal mode (SLM) dual-wavelength switchable erbium-doped fiber laser (DW-EDFL) based on polarization-maintaining fiber Bragg grating Fabry–Perot cavity (PMFBG-FP) cascaded multiple sub-ring cavities (MSCs) is proposed. A PMFBG-FP with a narrow-band transmission peak and MSCs was implemented as an optical filter to [...] Read more.

A single longitudinal mode (SLM) dual-wavelength switchable erbium-doped fiber laser (DW-EDFL) based on polarization-maintaining fiber Bragg grating Fabry–Perot cavity (PMFBG-FP) cascaded multiple sub-ring cavities (MSCs) is proposed. A PMFBG-FP with a narrow-band transmission peak and MSCs was implemented as an optical filter to achieve stable dual-wavelength laser output and guaranteed SLM status. By stretching the PMFBG, a highly stable dual-wavelength tunable output could be achieved with a maximum tuning interval of 0.17 nm. The optical signal-to-noise-ratio (OSNR) at dual-wavelength lasing was higher than 57 dB, and the optimal wavelength and power fluctuations within 0.5 h were 0.01 nm and 0.79 dB, respectively. Meanwhile, the measured linewidths of each wavelength were 1.55 kHz and 1.65 kHz, respectively. The measured polarization states of the two laser wavelengths were linear and orthogonal, with a degree of polarization (DOP) of nearly 100%. Full article

(This article belongs to the Section Lasers, Light Sources and Sensors)

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8 pages, 1573 KiB

Open AccessArticle

Digitally Chirped Multilayer Quantum Dot Lasers with Dual-Wavelength Lasing Emissions

by Yi-Jan Leo Sun, Pin-Hsien Hsieh and Gray Lin

Appl. Sci. 2019, 9(11), 2246; https://doi.org/10.3390/app9112246 - 31 May 2019

Viewed by 2191

Abstract

The dual-wavelength lasing emissions of digitally chirped multilayer quantum dot (QD) lasers are investigated both experimentally and theoretically. The two lasing wavelengths are both identified as ground-state (GS) emissions but originated from different stacks of QD multilayers. The lasing spectra exhibited broadening and [...] Read more.

The dual-wavelength lasing emissions of digitally chirped multilayer quantum dot (QD) lasers are investigated both experimentally and theoretically. The two lasing wavelengths are both identified as ground-state (GS) emissions but originated from different stacks of QD multilayers. The lasing spectra exhibited broadening and splitting properties by injecting more current. Moreover, the wavelength-resolved light-current characteristics reveal that first GS lasing intensity upon the threshold of second GS transitions neither saturates nor droops with increasing injection current, but increases with slightly reduced slope efficiency. A theoretical model is developed for digitally chirped multilayer QD lasers. The simulation results qualitatively reproduce the experimental observations. Full article

(This article belongs to the Special Issue Photonic Crystals for Electromagnetic Applications)

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