Nonreciprocal optical devices play a pivotal role in modern optical systems and advanced quantum technologies. Nonreciprocal devices based on optical nonlinearity have garnered significant attention due to their compatibility with on-chip photonics fabrication techniques. However, when the opposite-propagating continuous waves are incident to such nonlinear nonreciprocal devices simultaneously, achieving dynamic nonreciprocity has remained a formidable challenge. In addition, the devices relying on nonlinear resonators suffer from limited bandwidths. In this paper, we theoretically propose a method for achieving an on-chip isolator and quasicirculator by employing a nonlinear Mach-Zehnder interferometer. Harnessing the chirality between self- and cross-Kerr nonlinearities in the nonlinear arm of the interferometer, our device achieves remarkable dynamic nonreciprocity. We obtain an isolation contrast of $\ensuremath{\geqslant}0.9$ for the optical isolator and fidelity of $\ensuremath{\geqslant}0.97$ for the optical quasicirculator, and a broad bandwidth of $20\phantom{\rule{3.33333pt}{0ex}}\text{nm}$ for both. Our protocol paves a way to realize a broadband on-chip nonlinear nonreciprocal device.Nonreciprocal optical devices play a pivotal role in modern optical systems and advanced quantum technologies. Nonreciprocal devices based on optical nonlinearity have garnered significant attention due to their compatibility with on-chip photonics fabrication techniques. However, when the opposite-propagating continuous waves are incident to such nonlinear nonreciprocal devices simultaneously, achieving dynamic nonreciprocity has remained a formidable challenge. In addition, the devices relying on nonlinear resonators suffer from limited bandwidths. In this paper, we theoretically propose a method for achieving an on-chip isolator and quasicirculator by employing a nonlinear Mach-Zehnder interferometer. Harnessing the chirality between self- and cross-Kerr nonlinearities in the nonlinear arm of the interferometer, our device achieves remarkable dynamic nonreciprocity. We obtain an isolation contrast of $\ensuremath{\geqslant}0.9$ for the optical isolator and fidelity of $\ensuremath{\geqslant}0.97$ for the optical quasicirculator, and a broad bandwidth of $20\phantom{\rule{3.33333pt}{0ex}}\text{nm}$ for both. Our protocol paves a way to realize a broadband on-chip nonlinear nonreciprocal device.

Physical Review AOct 8, 20246 citations

Nonlinear Optics

Werner H. Lauterborn, Thomas Kurz, Martin Wiesenfeldt

Springer eBooksJan 1, 19950 citations

Bistable optical devices by guided wave excitation

A. Köster, P. Martinot, Fabrice Pardo +3 more

Most of the intrinsic optical devices which have been studied in recent years consist of a Fabry-Perot resonator containing a nonlinear medium. The response time of such devices is determined by the transients associated with the high-Q resonator and the response time of the nonlinear medium. The fastest devices must be free of any Fabry-Perot cavity. The excitation of either surface plasmons at a nonlinear interface or guided waves in thin nonlinear films is a way to obtain an ultrafast bistable optical device. These two kinds of device have been studied.Most of the intrinsic optical devices which have been studied in recent years consist of a Fabry-Perot resonator containing a nonlinear medium. The response time of such devices is determined by the transients associated with the high-Q resonator and the response time of the nonlinear medium. The fastest devices must be free of any Fabry-Perot cavity. The excitation of either surface plasmons at a nonlinear interface or guided waves in thin nonlinear films is a way to obtain an ultrafast bistable optical device. These two kinds of device have been studied.

Conference on Lasers and Electro-OpticsJan 1, 19841 citation

Photon‐Pair Generation with a 100 nm Thick Carbon Nanotube Film

Kim Fook Lee, Ying Tian, He Yang +7 more

Nonlinear optics based on bulk materials is the current technique of choice for quantum-state generation and information processing. Scaling of nonlinear optical quantum devices is of significant interest to enable quantum devices with high performance. However, it is challenging to scale the nonlinear optical devices down to the nanoscale dimension due to relatively small nonlinear optical response of traditional bulk materials. Here, correlated photon pairs are generated in the nanometer scale using a nonlinear optical device for the first time. The approach uses spontaneous four-wave mixing in a carbon nanotube film with extremely large Kerr-nonlinearity (≈100 000 times larger than that of the widely used silica), which is achieved through careful control of the tube diameter during the carbon nanotube growth. Photon pairs with a coincidence to accidental ratio of 18 at the telecom wavelength of 1.5 µm are generated at room temperature in a ≈100 nm thick carbon nanotube film device, i.e., 1000 times thinner than the smallest existing devices. These results are promising for future integrated nonlinear quantum devices (e.g., quantum emission and processing devices).Nonlinear optics based on bulk materials is the current technique of choice for quantum-state generation and information processing. Scaling of nonlinear optical quantum devices is of significant interest to enable quantum devices with high performance. However, it is challenging to scale the nonlinear optical devices down to the nanoscale dimension due to relatively small nonlinear optical response of traditional bulk materials. Here, correlated photon pairs are generated in the nanometer scale using a nonlinear optical device for the first time. The approach uses spontaneous four-wave mixing in a carbon nanotube film with extremely large Kerr-nonlinearity (≈100 000 times larger than that of the widely used silica), which is achieved through careful control of the tube diameter during the carbon nanotube growth. Photon pairs with a coincidence to accidental ratio of 18 at the telecom wavelength of 1.5 µm are generated at room temperature in a ≈100 nm thick carbon nanotube film device, i.e., 1000 times thinner than the smallest existing devices. These results are promising for future integrated nonlinear quantum devices (e.g., quantum emission and processing devices).

Advanced MaterialsApr 24, 201737 citations

Nonlinear Optics

Wolfgang Demtröder

Springer eBooksJan 1, 20140 citations

20\phantom{\rule{3.33333pt}{0ex}}\text{nm}

for both. Our protocol paves a way to realize a broadband on-chip nonlinear nonreciprocal device.