Parity-time symmetry in a single-loop photonic system

Fan, Zhiqiang; Dai, Zheng; Qiu, Qi; Yao, Jianping

doi:10.1109/jlt.2020.2982911

Cited by 10 publications

(9 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The wavelength of the output lasing is 1550 nm, and the OSNR is 43.0 dB without any parasitic lasing in the wavelength range of 10 nm, demonstrating the excellent mode selection performance. Compared with the references [15,16], the suppression ability of side modes is slightly improved in the proposed scheme. In the inset of Fig.…”

Section: Resultsmentioning

confidence: 87%

“…Thus, the measured linewidth should be regarded as a conservative estimation relative to the actual linewidth. Compared with the references [15,16], our experimental setup can also reduce the lasing linewidth to the sub-kHz level. In fact, the limit factors for the laser linewidth include laser gain, cavity length and output power [30].…”

Section: Resultsmentioning

confidence: 97%

“…2. Since the evolution process of eigenfrequencies is mainly reflected in the second term of (3), in order to more clearly show the difference between the real part and imaginary part from PT symmetry to PT symmetry breaking, w in (3) is set as 0 [10,15,16,18,22].…”

Section: B Pt Symmetrymentioning

confidence: 99%

“…However, in practice, the implementation is challenging to ensure the precise consistency of two optical loops, which greatly increases the difficulty of experimental operation. In view of this, to realize stable single-mode lasing, a PT-symmetric fiber ring laser with a single physical loop has been studied more widely in the field of optics [14][15][16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

“…Compared with the references [14,15], a complicated Sagnac loop containing a polarization beam splitter (PBS) and two PCs is substituted by a simplified Sagnac loop only including a single PC, which simplifies system structure; more importantly, just by adjusting a PC, leading to nonreciprocal light transmission to meet the PT symmetry, which makes the system operation more convenient. In addition, in the reference [16], a Sagnac loop based on a microdisk resonator (MDR) and two PCs was used to generate a PT symmetric single-mode laser, by comparison, fabrication process of the device is complicated, and it is difficult to achieve coupling between the integrated device and optical fiber; furthermore, additional temperature control is required to tune lasing wavelength, which further increases structural complexity and system cost. Therefore, the proposed configuration has prominent advantages in terms of system cost and practical operation.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Stable and Tunable PT-Symmetric Single-Longitudinal-Mode Fiber Laser Using a Nonreciprocal Sagnac Loop

Tao

Wang

et al. 2023

IEEE Access

View full text Add to dashboard Cite

A stable and tunable parity-time (PT) symmetric single-longitudinal-mode fiber laser using a nonreciprocal Sagnac loop is proposed, which is experimentally and numerically demonstrated. The nonreciprocal Sagnac loop only including a 3-dB optical coupler (OC) and a polarization controller (PC) is incorporated into a fiber ring cavity, in which nonreciprocal light transmission between the frequencydegenerate clockwise (CW) and counterclockwise (CCW) resonator modes is induced to suppress multiplelongitudinal-mode oscillation of the laser. The two light paths along the CW and CCW directions in the Sagnac loop are respectively defined as the gain and loss loop of the PT-symmetric laser, due to a controllable birefringence induced by the PC. By controlling the polarization states of the two light waves, the PT symmetry is broken when the gain coefficient is larger than the coupling coefficient, single-mode lasing is thus achieved. Experimental results show that the optical signal to noise ratio (OSNR) of the single-mode lasing at 1550 nm is 43.0 dB, proving the great superiority of PT symmetry for lasing mode selection. By tuning an optical tunable band-pass filter incorporated into the fiber cavity, the wavelength of output singlemode lasing varies from 1530 to 1560 nm, and their 3-dB Lorentzian linewidth varies within a range from 529 to 687 Hz. During a 30-min observation period, the variations of wavelength drift and OSNR of the single-mode lasing are less than 6 pm and 2.42 dB, respectively. The advantages of the proposed scheme are obvious, which include simple structure, low cost, simple operation, and good stability.

show abstract

Section: Resultsmentioning

confidence: 87%

Section: Resultsmentioning

confidence: 97%

Section: B Pt Symmetrymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Stable and Tunable PT-Symmetric Single-Longitudinal-Mode Fiber Laser Using a Nonreciprocal Sagnac Loop

Tao

Wang

et al. 2023

IEEE Access

View full text Add to dashboard Cite

show abstract

Polarimetric parity-time symmetry fiber laser with switchable and tunable orthogonal single-polarization narrow-linewidth output

Yin

Gao

et al. 2023

Results in Physics

View full text Add to dashboard Cite

Tunable single-longitudinal-mode narrow linewidth Brillouin fiber laser based on PT symmetry

Tao¹,

Wang²,

Xia³

et al. 2023

Laser Phys. Lett.

View full text Add to dashboard Cite

A tunable single-longitudinal-mode (SLM) narrow linewidth Brillouin fiber laser based on parity-time (PT) symmetry is proposed and experimentally demonstrated. In the proposed scheme, the dual selecting-mode mechanism is employed to achieve the SLM operation. The first, a narrow-band gain curve induced by stimulated Brillouin scattering (SBS) can be acted as a filter for selecting mode preliminary in the fiber ring cavity. The second, a PT-symmetric structure is formed by using a Sagnac loop, in which by adjusting a single polarization controller, the PT symmetry can be broken, resulting in the SLM oscillation. The SBS effect can be further beneficial to the linewidth narrowing. Using the proposed scheme, the SLM lasing with an optical signal to noise ratio of 50.1 dB and an ultra-narrow linewidth of 300 Hz at 1547.90 nm is obtained. Compared with the original linewidth of pump laser, the linewidth-reduction ratio can be up to 680 times. The available wavelength ranges from 1528.4 to 1563.4 nm, covering 35 nm. The key advantage of the proposed laser is that by constructing a simple Sagnac loop, the SLM selection based on PT symmetry and linewidth narrowing benefiting from SBS effect are accomplished simultaneously. Moreover, it is worth noting that the wavelength tunability is virtually unrestricted, only depending on the pump wavelength.

show abstract

Parity-time symmetry in a single-loop photonic system

Cited by 10 publications

References 31 publications

Stable and Tunable PT-Symmetric Single-Longitudinal-Mode Fiber Laser Using a Nonreciprocal Sagnac Loop

Stable and Tunable PT-Symmetric Single-Longitudinal-Mode Fiber Laser Using a Nonreciprocal Sagnac Loop

Polarimetric parity-time symmetry fiber laser with switchable and tunable orthogonal single-polarization narrow-linewidth output

Tunable single-longitudinal-mode narrow linewidth Brillouin fiber laser based on PT symmetry

Contact Info

Product

Resources

About