Interruption system configured to control the transmission of an optical signal

EP4677778A1Pending Publication Date: 2026-01-14LAIR LIQUIDE SA POUR LETUDE & LEXPLOITATION DES PROCEDES GEORGES CLAUDE +1
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Patent Information

Application Number
EP2023708807
Authority / Receiving Office
EP · EP
Patent Type
Applications
Current Assignee / Owner
Priority Date
2022-03-11
Filing Date
2023-03-07
Publication Date
2026-01-14

AI Technical Summary

Technical Problem

Existing systems for interrupting optical signal transmission, such as MEMs, thermo-optical, and electro-optical systems, have low switching speeds and are not suitable for short data packets, requiring high power for control signals, especially at room temperature, making them inefficient for controlling transmission of short data packets.

Method used

A semiconductor optical amplifier system cooled to cryogenic temperatures (≥10 K, preferably ≥40K) to reduce the power required for switching, allowing low-power control signals to manage the transmission and extinction ratio, enabling efficient switching between transmission states without electrical powering.

Benefits of technology

The system achieves low-power switching and high extinction ratio, enabling efficient control of optical signal transmission for both short and long data packets, with reduced energy consumption and improved performance compared to existing systems.

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Abstract

The invention relates to an interruption system (10) configured to control the transmission of an optical signal, the system comprising a semiconductor optical amplifier (AMP, AMP1, AMP2) configured to receive:  an input optical signal (SOE, SOE1, SOE2), and  a control signal (SC, SC1, SC2) configured to control the semiconductor optical amplifier (AMP, AMP1, AMP2), characterized in that the interruption system further comprises a cooling device (12, 12-1, 12-2) configured to cool the semiconductor optical amplifier (AMP, AMP1, AMP2) to a temperature greater than or equal to 10 K, preferably greater than or equal to 40 K, and to cool the optical modulator to a temperature less than or equal to 90 K, preferably less than or equal to 80 K.
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Description

[0001] INTERRUPTION SYSTEM CONFIGURED TO CONTROL THE TRANSMISSION OF AN OPTICAL SIGNAL

[0002] FIELD OF THE INVENTION

[0003] The invention relates to an interruption system configured to control the transmission of an input optical signal.

[0004] STATE OF THE ART

[0005] It is known to use different systems to interrupt the transmission of an input signal.

[0006] EP 2 242 191 A2 describes a relay apparatus, a signal processing apparatus and an optical transmission system applied to a passive optical network. US 10 097 281 B1 describes an optoelectronic data link system involving cryogenic cooling. US 2014 / 139909 A1 describes an optical amplification device.

[0007] Microelectromechanical systems (MEMs), thermo-optical systems, electro-optical systems, and acousto-optical systems are useful systems for transmitting relatively long data packets. However, these systems have the disadvantage, due to their intrinsic limitations, of having a relatively low switching speed between a transmission state and a transmission stop state. These interruption systems are therefore not suitable for an input signal comprising relatively short data packets.

[0008] In an optoelectronic amplifier, such as a semiconductor optical amplifier, the interruption is controlled by a control signal. When the power of the control signal is too low, the amplifier is no longer powered and is no longer able to receive the input signal. When the power of the control signal is sufficient to power the semiconductor optical amplifier, the latter receives the input signal and is able to amplify it.

[0009] There are all-optical input signal transmission interruption systems. In all-optical interruption systems, a control signal is constituted by an optical signal. The optical control signal is a light pump signal which is used to supply power to the semiconductor optical amplifier and control the on or off state of the amplifier depending on the power of the light pump signal. The use of an optical control signal makes it possible to switch between a state allowing transmission and a state interrupting the transmission of the input signal to the semiconductor optical amplifier for a very short time, compared to the length of the data packets of the input signal. These interruption systems are therefore suitable for an input signal comprising relatively short and / or relatively long data packets.

[0010] However, at room temperature, the use of an all-optical interruption system, such as a solid-state optical amplifier, is almost impossible, due to the power of the control signal that would be required by the solid-state optical amplifier.

[0011] There is therefore a need to be able to control the transmission of an input optical signal adapted to the length of the data packets, more particularly to relatively short data packets, while requiring low power for the control signal.

[0012] The invention aims to provide a system to meet these needs.

[0013] BRIEF DESCRIPTION OF THE INVENTION

[0014] To this end, the present invention relates to an interruption system configured to control the transmission of an optical signal, the system comprising a semiconductor optical amplifier (AMP, AMP1, AMP2) configured to receive:

[0015] • an optical input signal (SOE, SOE1, SOE2), and

[0016] • a control signal (SC, SCI, SC2) configured to control the semiconductor optical amplifier (AMP, AMP1, AMP2), characterized in that the interruption system further comprises a cooling device (12, 12-1, 12-2) configured to cool the semiconductor optical amplifier (AMP, AMP1, AMP2) to a temperature greater than or equal to 10 K, preferably greater than or equal to 40 K and to cool the optical modulator to a temperature less than or equal to 90 K, preferably less than or equal to 80 K.

[0017] Advantageously, cooling the optical amplifier to a cryogenic temperature makes it possible to ensure switching between transmission and stopping of the transmission of the input optical signal to the semiconductor optical amplifier without requiring significant power from the control signal. At such a temperature, the semiconductor optical amplifier does not need to be electrically powered. Since the switching energy is low, the latter can be transmitted by a control signal, for example in the form of an optical signal. Advantageously, the fact that the interruption system according to the invention is subjected to a temperature greater than or equal to 10 K, preferably greater than or equal to 40 K and less than or equal to 90 K, preferably less than or equal to 80 K allows the semiconductor optical amplifier to have an extinction ratio greater than 30 dB.The extinction ratio of the same amplifier at room temperature is of the order of 20 dB.

[0018] The extinction ratio corresponds to the power variation, in dB, between the power of the optical signal at the output of the semiconductor optical amplifier in the on state and the power of the optical signal at the output of the amplifier in the off state. The on state occurs when the control signal provides enough energy to power the semiconductor optical amplifier. Conversely, the off state occurs when the control signal does not provide enough energy to power the semiconductor optical amplifier. It should be noted that in the off state the power is non-zero due to the existence of noise.

[0019] Advantageously, the interruption system may also comprise one or more of the following features, considered individually or in any technically possible combination: the control signal is an electrical signal; and / or the control signal is an optical signal; and / or the semiconductor optical amplifier is a bidirectional component configured to receive the input optical signal and the control optical signal in opposite directions; and / or the cooling device is direct; and / or the cooling device is indirect; and / or the cooling device is active; and / or the cooling device is passive;and / or the cooling device comprises a temperature controller, the temperature controller being configured to maintain the semiconductor optical amplifier at a target temperature with a margin less than or equal to +500 mK, preferably less than or equal to +200 mK, and greater than or equal to -500 mK, preferably greater than or equal to -200 mK; and / or the semiconductor optical amplifier forms part of an integrated photonic circuit; and / or the interruption system comprises several semiconductor optical amplifiers each configured to receive:;

[0020] • a respective optical input signal, and

[0021] • a respective control signal, the control signal being configured to control the semiconductor optical amplifier; and / or at least two semiconductor optical amplifiers are at a different temperature; and / or the same cooling device is configured to cool at least two semiconductor optical amplifiers; and / or the cooling device comprises a device for regulating the temperature of at least two semiconductor optical amplifiers; and / or the control signal is a shared control signal for each of the semiconductor optical amplifiers; and / or the optical control signal and the input optical signal have different polarizations;and / or the wavelength of the input optical signal differs from the wavelength of the control optical signal by at least 0.05 nm, preferably by at least 0.1 nm, preferably by at least 0.5 nm, preferably by at least 1 nm, preferably by at least 1.5 nm and even more preferably by at least 5 nm; and / or the power of the control optical signal is greater than or equal to -30 dBm, preferably greater than or equal to -10 dBm and less than or equal to +10 dBm, preferably less than or equal to +5 dBm; and / or the power of the input optical signal is less than the power of the control optical signal by at least 5 dB; and / or the cooling device comprises:;

[0022] • a bar made of a material having a thermal conductivity greater than or equal to 20 watts per meter-kelvin on which the amplifiers are placed,

[0023] • a cold point placed at a first location on the bar, and

[0024] • a temperature control device comprising a temperature sensor arranged at a second location on the bar. BRIEF DESCRIPTION OF THE FIGURES

[0025] The invention will be better understood in light of the following description which is given for information purposes only and which is not intended to limit said invention, accompanied by the figures below: Figure 1 is a schematic representation of an interruption system according to the invention, according to a first embodiment, Figure 2 is a schematic representation of an interruption system according to the invention, according to a second embodiment, Figure 3a is a schematic representation of an interruption system according to the invention, according to a third embodiment, Figure 3b is a schematic representation of an interruption system according to the invention, according to a fourth embodiment, Figure 4 is a schematic representation of an interruption system according to the invention, according to a fifth embodiment, Figure 5 is a schematic representation of an interruption system according to the invention, according to a sixth embodiment,Figure 6 is a schematic representation of an interruption system according to the invention, according to a seventh embodiment, Figure 7 is a schematic representation of an interruption system according to the invention, according to an eighth embodiment, Figure 8 is a schematic representation of an interruption system according to the invention, according to a ninth embodiment, and Figure 9 is a schematic representation of an interruption system according to the invention, according to a tenth embodiment.,

[0026] DETAILED DESCRIPTION OF THE INVENTION

[0027] Figure 1 shows an interruption system 10 configured to control the transmission of an input optical signal SOE, the system comprising a semiconductor optical amplifier (AMP, AMP1, AMP2) configured to receive:

[0028] • an optical input signal (SOE, SOE1, SOE2), and

[0029] • a control signal (SC, SCI, SC2) configured to control the semiconductor optical amplifier (AMP, AMP1, AMP2), characterized in that the interruption system further comprises a cooling device (12, 12-1, 12-2) configured to cool the semiconductor optical amplifier (AMP, AMP1, AMP2) to a temperature greater than or equal to 10 K, preferably greater than or equal to 40 K and to cool the optical modulator to a temperature less than or equal to 90 K, preferably less than or equal to 80 K.

[0030] The control signal SC is the signal conditioning the transmission and amplification of the input optical signal SOE by the semiconductor optical amplifier AMP.

[0031] The SC control signal can be electrical or optical.

[0032] Advantageously, when the SC control signal is optical, the control signal can be remote.

[0033] Advantageously, the interruption system according to the invention being all-optical, the latter is not sensitive to electromagnetic disturbances.

[0034] Advantageously, the control signal SC can be used to provide the power supply to the semiconductor optical amplifier AMP.

[0035] It has been surprisingly noted that the semiconductor optical amplifier AMP provides a non-zero gain when the latter is subjected to a cryogenic temperature, greater than or equal to 10 K, preferably greater than or equal to 40 K and less than or equal to 90 K, preferably less than or equal to 80 K, and that a low power supply, of the order of a few milliamps, is provided. Since the semiconductor optical amplifier AMP is low-power at this temperature, it is then possible to provide the switching energy to the semiconductor optical amplifier AMP by the control signal SC, in the form of an optical signal.

[0036] In this way the beam of a laser used to provide the optical SC control signal can also be used to power the semiconductor optical amplifier AMP.

[0037] In an all-optical interruption system according to the invention, the input optical signal SOE has a power different from that of the control signal SC. Preferably, the power of the input optical signal SOE is lower than the power of the control signal so that the semiconductor optical amplifier AMP distinguishes the control signal SC from the input optical signal SOE. The control signal of a semiconductor amplifier AMP is the signal having the greatest power among the input optical signal SOE and the control signal SC.

[0038] The signal with the highest power between the input optical signal SOE and the control signal SC takes the role of control signal even if this is not its initial function.

[0039] Thus, preferably the power of the input optical signal SOE is at least 5 dB lower than the power of the control signal SC, preferably at least 10 dB lower.

[0040] In one embodiment, the power of the control signal is greater than or equal to -30 dBm, preferably greater than or equal to -10 dBm and less than or equal to +10 dBm, preferably less than or equal to +5 dBm. The dBm is a unit that expresses power in decibels (dB) relative to a reference value of 1 milliwatt (mW).

[0041] The control signal SC may have a different polarization than the input optical signal SOE. For example, the control signal SC is in transverse electric mode, respectively transverse magnetic mode and the input optical signal SOE is in transverse magnetic mode, respectively transverse electric mode.

[0042] The AMP semiconductor optical amplifier is a bidirectional optoelectronic component. The SOE input optical signal and the SC optical control signal can be supplied together using a single optical fiber at one of the terminals of the AMP semiconductor optical amplifier.

[0043] In one embodiment, illustrated in Figure 2, the input optical signal SOE and the control signal SC are supplied to the semiconductor optical amplifier AMP in opposite directions via the terminals arranged on either side of the amplifier. The input optical signals SOE and control signals SC are considered counter-directional.

[0044] To facilitate the understanding of Figure 2, the SC control signal and the SOS output optical signal have been represented separately to define the propagation direction of these signals. However, the SC control signal and the SOS output optical signal are counter-propagating signals at the same optical fiber.

[0045] In another embodiment, regardless of whether the control signal SC and the input optical signal SOE have a different polarity or are transmitted to two opposite terminals of the semiconductor optical amplifier AMP, the wavelength of the control signal SC and the input optical signal SOE may be different. For example, the wavelength of the control signal SC and the input optical signal SOE is different by at least 0.05 nm, preferably by at least 0.1 nm, preferably by 0.5 nm, preferably by at least 1 nm, preferably by at least 1.5 nm and even more preferably by at least 5 nm.

[0046] In one embodiment, the interrupt system 10 may comprise N semiconductor optical amplifiers, each configured to receive: a respective input optical signal SOE1, SOE2, . . . SOEN, and a respective control signal SCI, SC2, ..., SCN, the control signal being configured to control the semiconductor optical amplifier AMP1, AMP2, ..., AMPN.

[0047] At least one of the N semiconductor optical amplifiers AMP1, AMP2, . . ., AMPN is configured to be cooled by the cooling device 12.

[0048] The cooling device can be the same for each of the N semiconductor optical amplifiers AMP1, AMP2, . . ., AMPN.

[0049] The cooling device may be the same for at least two of the N semiconductor optical amplifiers AMP1, AMP2, . . ., AMPN.

[0050] Each of the N semiconductor optical amplifiers AMP1, AMP2, . . ., AMPN can be cooled by a respective cooling device 12-1, 12-2 (illustrated in Figure 3a).

[0051] Preferably, each of the semiconductor optical amplifiers AMP1, AMP2 of the interruption system 10 is cooled by the cooling device to a cryogenic temperature, greater than or equal to 10 K, preferably greater than or equal to 40 K and less than or equal to 90 K, preferably less than or equal to 80 K.

[0052] For the remainder of the description, for ease of understanding, reference will only be made to two semiconductor optical amplifiers AMP1, AMP2. However, the description of the embodiments involving two semiconductor optical amplifiers AMP1, AMP2 can also be applied to N semiconductor optical amplifiers AMP1, AMP2, . . ., AMPN.

[0053] Figure 3a illustrates an interruption device 10 comprising two semiconductor optical amplifiers AMP1, AMP2. For each of the two semiconductor optical amplifiers AMP1, AMP2, the input optical signals SOE1, SOE2 and the control signals SCI, SC2 are respectively jointly supplied using a single optical fiber to a terminal of the semiconductor optical amplifier.

[0054] Each of the two semiconductor optical amplifiers AMP1, AMP2 receives a respective optical input signal SOE1, SOE2 and a control signal SCI, SC2, so as to provide an optical output signal S0S1, S0S2 respectively.

[0055] Figure 3b is almost identical to Figure 3a and illustrates an interruption system 10 according to the invention, where a first semiconductor optical amplifier AMP1 receives a first control signal SCI in a first direction and a second semiconductor optical amplifier AMP2 receives a second control signal SC2 in a second direction opposite to the first direction.

[0056] In the same way as for Figure 2, the control signal SC2 and the output optical signal S0S2 have been represented separately to define the propagation direction of these signals. However, the control signal SC2 and the output optical signal S0S2 are counter-propagating signals at the level of the same optical fiber.

[0057] In one embodiment, a first semiconductor optical amplifier AMP 1 receives a first input optical signal SOE1 in a first direction and a second semiconductor optical amplifier AMP2 receives a second input optical signal SOE2 in a second direction opposite to the first direction. Each of the two semiconductor optical amplifiers AMP1, AMP2 is a bidirectional component.

[0058] The two semiconductor optical amplifiers AMP1, AMP2 are cooled by the same cooling device 12 or a respective cooling device.

[0059] Advantageously, the cooling device 12 can be shared by using the same cooling device for two semiconductor optical amplifiers AMP1, AMP2.

[0060] The two semiconductor optical amplifiers AMP1, AMP2 can be kept at the same temperature to amplify the input optical signals SOE1, SOE2 over the same wavelength range. This makes it possible, for example, to simultaneously amplify two signals belonging to the same wavelength range but with different operating points.

[0061] Alternatively, two semiconductor optical amplifiers AMP1, AMP2 may be maintained at a different temperature to amplify the input optical signals SOE1, SOE2 over a different wavelength range. For example, two semiconductor optical amplifiers AMP1, AMP2 are maintained at temperatures having a difference of, for example, 5K or more, and of, for example, 10K or more. In this way, the input signals SOE1, SOE2 may be amplified over different bandwidths.

[0062] In one embodiment, illustrated in Figure 4, the same control signal SC is shared for two semiconductor optical amplifiers AMP1, AMP2.

[0063] Advantageously, in this way switching between transmission and interruption of data transmission can be ensured simultaneously at the level of the semiconductor optical amplifiers AMP1, AMP2.

[0064] In the same way as in the embodiment illustrated in Figure 4, where the control signal SC is shared, the input signal can be shared. A single input signal SOE could be divided into two and supplied to two semiconductor optical amplifiers AMP1, AMP2.

[0065] In one embodiment, the input optical signal SOE and the control signal SC are respectively shared for at least two amplifiers.

[0066] Advantageously, the same amplified signal can be supplied to separate locations simultaneously.

[0067] In one embodiment, the input optical signal may be pooled, while each solid-state optical amplifier receives a respective control signal.

[0068] Advantageously, in this way it can be chosen, for the same SOE input optical signal, to choose at least one semiconductor optical amplifier to amplify the input optical signal.

[0069] In one embodiment, the shared input optical signal is supplied to two semiconductor optical amplifiers AMP1, AMP2 maintained at two different temperatures to amplify the input optical signal SOE over two different bandwidths.

[0070] In one embodiment, the at least one semiconductor optical amplifier AMP, AMP1, AMP2 is a discrete component.

[0071] Alternatively, a single semiconductor optical amplifier AMP or a plurality of semiconductor optical amplifiers AMP1, AMP2 may form part of an integrated circuit 22, as illustrated in FIG. 5. The integrated circuit 22 is, for example, a photonic integrated circuit.

[0072] The cooling device 12 of the interruption system 10 is preferably a cryogenic cooling device.

[0073] The cooling device 12 may be indirect. The cooling device is considered indirect in the case where a cooling means does not act directly on the semiconductor optical amplifier AMP but on an element, for example a thermally conductive element on which the semiconductor optical amplifier AMP is arranged. The thermally conductive element, cooled by a cooling means, will in turn cool, by thermal conduction, the semiconductor optical amplifier AMP.

[0074] An indirect cooling device 12 may for example be formed by a thermally conductive bar which will be cooled at one of its ends by a cooling means. The bar is configured to receive at least one semiconductor optical amplifier AMP.

[0075] Advantageously, an indirect cooling device makes it possible to share a cooling means for several semiconductor optical amplifiers AMP, AMP1, AMP2. The bar can receive at least two semiconductor optical amplifiers AMP, AMP1, AMP2 on a thermally conductive bar, for example arranged at different locations.

[0076] Alternatively, the cooling device 12 may be direct. The direct cooling device 12 is a device configured to apply a thermal variation directly to the semiconductor optical amplifier AMP. The temperature control is carried out directly at the semiconductor optical amplifier AMP.

[0077] A direct cooling device can be formed by a dedicated cooling means locally cooling the semiconductor optical amplifier(s) AMP, AMP1, AMP2.

[0078] Advantageously, it is not necessary to use a thermally conductive structure on which the semiconductor optical amplifier(s) AMP, AMP1, AMP2 would be arranged. Advantageously, the use of a direct cooling device 12 makes it possible to better control the temperature supplied to the at least one semiconductor optical amplifier AMP, AMP1, AMP2.

[0079] Also, in the context of a direct cooling device 12, it is easier and faster to compensate for a variation at the level of a semiconductor optical amplifier AMP. It is not necessary to wait for a conductive element to reach the desired temperature at the location where the semiconductor optical amplifier AMP is arranged.

[0080] The cooling device 12 may be a passive cooling device.

[0081] For example, a passive cooling device may be a heat sink in contact with the semiconductor optical amplifier AMP. The heat sink radiates outward from the semiconductor optical amplifier AMP, such as a radiant heat energy extraction device. A passive cooling device 12 may also be formed by a cooling circuit comprising liquid nitrogen.

[0082] A passive cooling device is devoid of energy input. Advantageously, the energy consumption to maintain the semiconductor optical amplifier(s) AMP, AMP1, AMP2 at a cryogenic temperature is reduced.

[0083] A cooling device 12 may be active. An active cooling device requires an energy input to ensure the cooling of the semiconductor optical amplifier AMP. Despite the need for an energy input, the temperature regulation of a semiconductor optical amplifier AMP is faster and more reliable due to the control of the cooling device, by regulating its power supply.

[0084] To ensure precise temperature control of the at least one or each of the semiconductor optical amplifiers AMP1, AMP2, the cooling device 12, 12-1, 12-2 may comprise a temperature regulator 14, 14-1, 14-2 (illustrated in FIG. 7).

[0085] Preferably, the temperature regulator 14, 14-1, 14-2 is configured to maintain the semiconductor optical amplifier AMP, AMP1, AMP2 at a target temperature with a margin less than or equal to +500 mK, preferably less than or equal to +200 mK, and greater than or equal to -500 mK, preferably greater than or equal to -200 mK.

[0086] Advantageously, precise control of the temperature of the semiconductor optical amplifier AMP, AMP1, AMP2 makes it possible to precisely control the wavelength range over which the latter amplifies the signal. Also, the temperature regulator 14, 14-1, 14-2 makes it possible to compensate for the heat supplied by the control signal to the semiconductor optical amplifier AMP, AMP1, AMP2. The greater the power of the control signal SC, the greater the heat transmitted by this signal. Therefore, to ensure the proper thermal regulation of the temperature of the semiconductor optical amplifier AMP, AMP1, AMP2, it is important to take into account the thermal impact of the control signal SC.

[0087] The temperature controller 14 may be used to control the temperature of one or more of the semiconductor optical amplifiers AMP, AMP1, AMP2, as illustrated in FIG. 6.

[0088] Figure 7 represents an interruption system according to the invention in which each of the two semiconductor optical amplifiers AMP1, AMP2 comprises a respective cooling device 12-1, 12-2 and a temperature regulator 14-1, 14-2.

[0089] Such a system, using respective cooling devices and temperature regulators, allows better control of the temperature of each of the two semiconductor optical amplifiers AMP1, AMP2.

[0090] Figure 8 illustrates an embodiment of the cooling device 14. The cooling device may comprise: a bar 16 made of a material having a high thermal conductivity on which the N amplifiers are arranged (in the case of figure 8, two amplifiers AMP1 and AMP2 are illustrated), a cold point 18 arranged at a first location E1 of the bar 16, and a temperature regulation device 14 comprising a temperature sensor 20 arranged at a second location E2 of the bar.

[0091] Preferably, the bar 16 has a thermal conductivity greater than or equal to 20 watts per meter-kelvin. The temperature at different locations of the bar 30 is different.

[0092] In one embodiment, the bar 16 is made of copper.

[0093] The bar may be made of a material having high thermal conductivity and the presence of a cold point 18 makes it possible to create a temperature gradient between the first location E1 where the cold source 18 is arranged and an end E2 of the bar 16.

[0094] With such a temperature gradient, the positioning of the semiconductor optical amplifiers AMP1, AMP2 is important to be at a desired target temperature T1, T2. The temperature of the semiconductor optical amplifiers AMP1, AMP2 arranged on the bar 16 is conditioned by their location on the bar 16.

[0095] The cold point 18 corresponds to a cooling means configured to cool the bar 16 at a particular location of this bar 16, corresponding to the first location EL

[0096] In this way, the amplifiers arranged closest to the cold point 18 have a colder temperature than the amplifiers furthest from the cold point 18.

[0097] Preferably, the cooling means used is a cryogenic cooler.

[0098] The cold point 18 is preferentially positioned at one end of the bar 16 to maximize the temperature gradient between a first end and a second end of the bar 16.

[0099] The positioning of a temperature sensor 20 at a second location E2 of the bar 16 makes it possible to determine the temperature of the bar 16 at this second location E2. The bar being made of a conductive material, it can be determined, from the measurement of the temperature sensor 34, at least approximately the temperature at each point of the bar 16 and more particularly at the positions where the semiconductor optical amplifiers AMP1, AMP2 are arranged.

[0100] Advantageously, from the measurement of the temperature at said second location E2 of the bar 16, the cooling device 12 can determine whether the temperature of the semiconductor optical amplifiers AMP1, AMP2 corresponds to the desired target temperature.

[0101] If the temperature of at least one semiconductor optical amplifier AMP1, AMP2 is different from the desired target temperature T1, T2, the cooling device 12 controls the regulating device 14 to regulate the temperature of the cold point 18 of the bar 16.

[0102] In another embodiment illustrated in Figure 9, the cooling device independently controls the temperature T1, T2 of the semiconductor optical amplifiers AMP1, AMP2. If one of the semiconductor optical amplifiers AMP1, AMP2 is not at a desired target temperature, the temperature controller 14 independently controls the temperature of that amplifier AMP1, AMP2.

[0103] Each of the semiconductor optical amplifiers AMP1, AMP2 is associated with a respective additional thermal source SI, S2. Each of the additional thermal sources SI, S2 is configured to individually regulate the temperature of one of the semiconductor optical amplifiers AMP1, AMP2.

[0104] In one embodiment, the N additional thermal sources are Peltier modules and / or resistors.

[0105] Advantageously, Peltier modules allow the temperatures of AMP1, AMP2 semiconductor optical amplifiers to be regulated by locally increasing or lowering their temperature.

[0106] Advantageously, the resistors make it possible to regulate the temperatures of the semiconductor optical amplifiers AMP1, AMP2 by locally increasing their temperature.

[0107] The embodiment, illustrated in Figure 9, is similar to the configuration illustrated in Figure 8, the temperature regulator 14 is however different. The temperature regulator 14 no longer regulates the temperature of the cold point 18 of the bar 16 but directly regulates the temperature of the additional thermal sources S1, S2.

[0108] The embodiment illustrated in Figure 9 may be devoid of the bar 16 and the cold point 18, the thermal sources SI and S2 providing the cold to the semiconductor amplifiers SI, S2.

[0109] The invention has been described above with the help of embodiments shown in the figures, without limitation of the general inventive concept.

[0110] Many other modifications and variations suggest themselves to those skilled in the art, after reflection on the various embodiments illustrated in this application.

[0111] These embodiments are given by way of example and are not intended to limit the scope of the invention, which is determined exclusively by the claims below.

[0112] In the claims, the word "comprising" does not exclude other elements or steps. The mere fact that different features are listed in mutually dependent claims does not indicate that a combination of these features cannot be advantageously used. Finally, any reference used in the claims should not be interpreted as a limitation of the scope of the invention.

Claims

DEMANDS 1. Interrupt system (10) configured to control the transmission of an optical signal, the system comprising a solid-state optical amplifier (AMP, AMP1, AMP2) configured to receive: • an optical input signal (SOE, SOE1, SOE2), and • a control signal (SC, SCI, SC2) configured to control the solid-state optical amplifier (AMP, AMP1, AMP2), characterized in that the interrupt system further comprises a cooling device (12, 12-1, 12-2) configured to cool the solid-state optical amplifier (AMP, AMP1, AMP2) to a temperature greater than or equal to 10 K, preferably greater than or equal to 40 K, and to cool the optical modulator to a temperature less than or equal to 90 K, preferably less than or equal to 80 K.

2. The interrupt system according to claim 1, characterized in that the control signal (SC, SCI, SC2) is an electrical signal.

3. The interrupt system according to claim 1, characterized in that the control signal (SC, SCI, SC2) is an optical signal.

4. The interrupt system according to claim 3, characterized in that the semiconductor optical amplifier (AMP, AMP1, AMP2) is a bidirectional component configured to receive the input optical signal (SOE, SOE1, SOE2) and the control optical signal (SC, SCI, SC2) in opposite directions.

5. The interruption system according to any one of the preceding claims, characterized in that the cooling device (12, 12-1, 12-2) is direct.

6. The interruption system according to any one of claims 1 to 4, characterized in that the cooling device (12, 12-1, 12-2) is indirect.

7. The interruption system according to any one of the preceding claims, characterized in that the cooling device (12, 12-1, 12-2) comprises a temperature regulator (14, 14-1, 14-2), the temperature regulator being configured to maintain the solid-state optical amplifier (AMP, AMP1, AMP2) at a target temperature (T1, T2) with a margin less than or equal to 500 mK, preferably less than or equal to 200 mK, and greater than or equal to -500 mK, preferably greater than or equal to -200 mK.

8. The interrupt system according to any one of the preceding claims, characterized in that the semiconductor optical amplifier (AMP, AMP1, AMP2) forms part of an integrated photonic circuit (22).

9. The interrupt system according to any one of the preceding claims, characterized in that the interrupt system (10) comprises several solid-state optical amplifiers (AMP, AMP1, AMP2) configured to receive each: a respective optical input signal (SOE, SOE1, SOE2), and a respective control signal (SC, SCI, SC2), the control signal being configured to control the solid-state optical amplifier (AMP, AMP1, AMP2).

10. The interrupting system according to claim 9, characterized in that at least two semiconductor optical amplifiers (AMP, AMP1, AMP2) are at a different temperature.

11. The interrupt system according to claim 9 or 10, characterized in that the control signal (SC, SCI, SC2) is a shared control signal for each of the semiconductor optical amplifiers (AMP, AMP1, AMP2).

12. The interruption system according to any one of claims 9 to 11, characterized in that the same cooling device (12, 12-1, 12-2) is configured to cool at least two semiconductor optical amplifiers (AMP, AMP1, AMP2).

13. The interrupt system according to any one of claims 3 to 12, characterized in that the optical control signal (SC, SCI, SC2) and the optical input signal (SOE, SOE1, SO2) have different polarizations.

14. The interrupting system according to any one of claims 3 to 13, characterized in that the wavelength of the input optical signal (SOE, SOE1, SO2) differs from the wavelength of the control optical signal (SC, SCI, SC2) by at least 0.05 nm, preferably by at least 0.1 nm, preferably by at least 0.5 nm, preferably by at least 1 nm, preferably by at least 1.5 nm and even more preferably by at least 5 nm.

15. The interrupting system according to any one of claims 3 to 14, characterized in that the power of the optical control signal (SC, SCI, SC2) is greater than or equal to -30 dBm, preferably greater than or equal to -10 dBm and less than or equal to +10 dBm, preferably less than or equal to +5 dBm.

16. The interrupt system according to any one of claims 3 to 15, characterized in that the power of the input optical signal (SOE, SOE1, SO2) is less than the power of the control optical signal (SC, SCI, SC2) by at least 5 dB.