Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Optics Letters

Optical bistability by photothermal displacement in prism coupling into planar waveguides

W. Lukosz, P. Pirani, V. Briguet

Published Apr 1, 1987• 18 citations
Publisher

Abstract

We have identified photothermal displacement as a mechanism for optical bistability (OB) in prism coupling into absorbing planar waveguides: heating by the absorbed incoupled power causes a buckling of the waveguide, a reduction in air-gap width, and thus an increase in incoupling efficiency and a positive feedback. We developed a theory of this OB that qualitatively agrees well with experimental results obtained by coupling argon-laser light into indium-tin oxide layers as strongly absorbing waveguides. This new OB is quite different from dispersive OB in prism or grating couplers caused by a power-dependent effective guide index.

DOI
10.1364/ol.12.000263

Related papers

Thermal Expulsion As A New Mechanism For Optical Bistability In Prism Coupling Into Planar Wavegaides

P. Pirani, V. Briguet, W. Lukosz

We investigated theoretically and experimentally a new type of cptical bistability (0B) in prism coupling into absorbing planar waveguides. Origin of this (B is the thermal expansion of the substrate (and the waveguiding film) and of the prism, due to heating by the part P = P of the incoupled power which is absorbed in the incoupling region. This expansion causes a reduction in the width d of the air gap between the prism coupler and the waveguide in the ompling region. Since the incoupling efficiency is a function of d, positive feedback, and therefore as, can occur. At the same input power Pa, the system has two bistable states, which differ in gap width d, in absorbed power Pa, and consequently in output (reflected) power PR. (see Fig. 1).

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Jan 1, 1987•1 citation

External Grating Couplers on Planar Waveguides as Integrated Optical Bistable Devices

V. Briguet, J. Kramer, W. Lukosz

The 'external' grating coupler is a diffraction grating pressed against the planar waveguide in a similar way as a prism coupler. Such couplers have, to the best of our knowledge, not been used in integrated optics. The couplers normally used are surface relief gratings on the waveguide. We report on a new type of optical bistability (OB) which occurs only with external but not with normal grating couplers. The air gap of width d, where 0≤d≤λ, plays an essential role in the OB mechanism.

Topical Meeting on Optical Bistability (OB)•Jan 1, 1988•0 citations

Optical bistability by photothermal displacement in grating coupler configuration: a theoretical interpretation

P. Vincent, Hassan Akhouayri, M. Nevière

The bistable behavior of an external grating coupler on a planar waveguide, which was previously discovered experimentally, is investigated by means of the electromagnetic theory of gratings. The theory accounts for all shapes of the observed hysteresis loops. The various shapes of the hysteresis loops, including the butterflylike shapes, are explained.

Journal of the Optical Society of America B•May 1, 1991•4 citations

Nonlinear Prism Coupler with Diffusion

Guy Vitrant, R. Reinisch, Jean-Claude Paumier +2 more

The salient question which arises when light is coupled via a grating or a prism into a waveguide exhibiting an intensity-dependent refractive index is whether switching occurs with or without bistability under appropriate detuning conditions. There are two prevailing theories. In the first1, a plane wave input is assumed leading to a uniform optically induced index change in the coupling region. In the second2, a finite width incident beam is assumed and the growth of the guided field under the coupler leads to an index change proportional to the local guided wave intensity. The first approach leads to optical bistability under certain detuning conditions, whereas the second results in switching only. Although it is known that plane wave analyses are inadequate when dealing with linear-nonlinear interfaces, bistability has been observed experimentally with nonlinear prism couplers3. Fundamentally the finite beam theoretical approaches are unable to predict bistability because no longitudinal feedback is included. Recently we showed that when non-locality is introduced into the optically induced refractive index change, longitudinal feedback occurs and bistability is predicted for the growing mode case4. However, the model used for the non-locality was artificial and resulted only in qualitative predictions. In this paper the nonlocality is modelled by the same equation used to describe heat transfer and carrier diffusion, leading to a quantitative estimate of the minimum diffusion length required for bistability.

Nonlinear Guided Waves and Their Applications•Jan 1, 1989•0 citations

Observation of optical bistabillty in ZnS waveguides

B. C. Svensson, G. Assanto, D. Kuchibhatla +3 more

Utilizing prism coupling of an argon laser beam into a nonlinear ZnS waveguide we have observed power-dependent optical bistability. We detuned the incidence angle by several linewidths from the optimal low power efficiency case. At this position we observed switching and hysteresis and verified the hysteresis loop to be bistable. The origin of the bistability we tentatively identified as a combination of intensity-dependent absorption and dispersion. Our conditions for bistability were different from those of W. Lukosz et al. in OPTICAL BISTABILITY III (Springer-Verlag, New York, 1986), p. 109.

Annual Meeting Optical Society of America•Jan 1, 1986•0 citations

Light - Induced - Desorption: A New Mechanism for Bistability In Integrated Optical Devices

W. Lukosz, V. Briguet

We have demonstrated a new mechanism for bistability in integrated optics, viz., light-induced-desorption of molecules from the waveguide surface by which the effective guide index N is changed. Bistability occurs if the desorption rate depends linearly on the incoupled power P' in an input coupler device (see Fig.1), and on the intracavity power in an IO Fabry Perot or ring resonator. This follows theoretically from an analysis analogous to that of the bistable radiation pressure driven waveguide pendulum.1

Topical Meeting on Optical Bistability (OB)•Jan 1, 1985•0 citations
We have identified photothermal displacement as a mechanism for optical bistability (OB) in prism coupling into absorbing planar waveguides: heating by the absorbed incoupled power causes a buckling of the waveguide, a reduction in air-gap width, and thus an increase in incoupling efficiency and a positive feedback. We developed a theory of this OB that qualitatively agrees well with experimental results obtained by coupling argon-laser light into indium-tin oxide layers as strongly absorbing waveguides. This new OB is quite different from dispersive OB in prism or grating couplers caused by a power-dependent effective guide index.
We investigated theoretically and experimentally a new type of cptical bistability (0B) in prism coupling into absorbing planar waveguides. Origin of this (B is the thermal expansion of the substrate (and the waveguiding film) and of the prism, due to heating by the part P = P of the incoupled power which is absorbed in the incoupling region. This expansion causes a reduction in the width d of the air gap between the prism coupler and the waveguide in the ompling region. Since the incoupling efficiency is a function of d, positive feedback, and therefore as, can occur. At the same input power Pa, the system has two bistable states, which differ in gap width d, in absorbed power Pa, and consequently in output (reflected) power PR. (see Fig. 1).
The 'external' grating coupler is a diffraction grating pressed against the planar waveguide in a similar way as a prism coupler. Such couplers have, to the best of our knowledge, not been used in integrated optics. The couplers normally used are surface relief gratings on the waveguide. We report on a new type of optical bistability (OB) which occurs only with external but not with normal grating couplers. The air gap of width d, where 0≤d≤λ, plays an essential role in the OB mechanism.
The salient question which arises when light is coupled via a grating or a prism into a waveguide exhibiting an intensity-dependent refractive index is whether switching occurs with or without bistability under appropriate detuning conditions. There are two prevailing theories. In the first1, a plane wave input is assumed leading to a uniform optically induced index change in the coupling region. In the second2, a finite width incident beam is assumed and the growth of the guided field under the coupler leads to an index change proportional to the local guided wave intensity. The first approach leads to optical bistability under certain detuning conditions, whereas the second results in switching only. Although it is known that plane wave analyses are inadequate when dealing with linear-nonlinear interfaces, bistability has been observed experimentally with nonlinear prism couplers3. Fundamentally the finite beam theoretical approaches are unable to predict bistability because no longitudinal feedback is included. Recently we showed that when non-locality is introduced into the optically induced refractive index change, longitudinal feedback occurs and bistability is predicted for the growing mode case4. However, the model used for the non-locality was artificial and resulted only in qualitative predictions. In this paper the nonlocality is modelled by the same equation used to describe heat transfer and carrier diffusion, leading to a quantitative estimate of the minimum diffusion length required for bistability.
Utilizing prism coupling of an argon laser beam into a nonlinear ZnS waveguide we have observed power-dependent optical bistability. We detuned the incidence angle by several linewidths from the optimal low power efficiency case. At this position we observed switching and hysteresis and verified the hysteresis loop to be bistable. The origin of the bistability we tentatively identified as a combination of intensity-dependent absorption and dispersion. Our conditions for bistability were different from those of W. Lukosz et al. in OPTICAL BISTABILITY III (Springer-Verlag, New York, 1986), p. 109.
We have demonstrated a new mechanism for bistability in integrated optics, viz., light-induced-desorption of molecules from the waveguide surface by which the effective guide index N is changed. Bistability occurs if the desorption rate depends linearly on the incoupled power P' in an input coupler device (see Fig.1), and on the intracavity power in an IO Fabry Perot or ring resonator. This follows theoretically from an analysis analogous to that of the bistable radiation pressure driven waveguide pendulum.1