Abstract: An optical semiconductor device includes a chassis that has an external wall, a feedthrough that penetrates the external wall of the chassis and has a projection portion projecting toward outside of the chassis from the external wall, a connection terminal that is electrically connected to a component mounted in the chassis and is on the projection portion of the feedthrough, a first temperature detector that is on an external face of the external wall of the chassis and detects a temperature of the chassis, and a flexible substrate of which an end is connected to the connection terminal and of which a portion spaced from the end is connected to the first temperature detector, wherein the first temperature detector is between the external wall and the flexible substrate.

Abstract: A driving condition for causing the tunable wavelength laser to conduct laser oscillation at a first wavelength is acquired. a driving condition for causing the tunable wavelength laser to conduct laser oscillation at the second wavelength is calculated. The tunable wavelength laser is driven based on the driving condition of the second wavelength, feedback control that changes the driving condition of the tunable wavelength laser based on a difference between an output of the wavelength sensing unit and the target value is performed, and the tunable wavelength laser is caused to oscillate at the second wavelength. The driving condition of the tunable wavelength laser obtained by the feedback control when oscillation has occurred at the second wavelength is stored in the memory. Thereafter, the tunable wavelength laser is driven with reference to the stored driving condition of the tunable wavelength laser.

Abstract: In the method for controlling a tunable wavelength laser, information designating an oscillation wavelength is inputted. A driving condition for causing laser oscillation at a first wavelength is acquired from a memory. A control value of wavelength characteristics of the etalon and a difference between the first wavelength and a second wavelength are referred to, and a control value of wavelength characteristics of the etalon for causing laser oscillation at the second wavelength is calculated. The control value of wavelength characteristics of the etalon are assigned to the tunable wavelength laser, and a wavelength is controlled so that a wavelength sensing result becomes a first target value. Information indicating a wavelength shift amount from the designated oscillation wavelength is inputted. The wavelength sensing result is calculated as a second target value. The wavelength is controlled so that the wavelength sensing result becomes the second target value.

Abstract: A method of controlling a wavelength tunable laser to control an oscillation wavelength based on a difference between a detection result of a wavelength by a wavelength detecting unit and a target value, the method includes: acquiring a first drive condition of the wavelength tunable laser to make the wavelength tunable laser oscillate at a first wavelength from a memory; calculating a second drive condition to drive the wavelength tunable laser at a second wavelength by referring to the first drive condition and a wavelength difference between the first wavelength and the second wavelength, the second wavelength differing from the first wavelength; and driving the wavelength tunable laser based on the second drive condition calculated at the calculating of the second drive condition.

Abstract: A method for switching a wavelength of a tunable wavelength laser, which is provided with a temperature control device for an etalon and a wavelength detecting section for identifying a wavelength of the laser by a front/back ratio of the etalon, the wavelength of the laser being set in a target wavelength on the basis of a detection result of the wavelength detecting section, and the method comprises: driving the laser at a first wavelength; suppressing output of light of the laser in response to a command indicating an optical output at a second wavelength; starting control of the temperature control device towards a second etalon temperature corresponding to the second wavelength; and before the etalon reaches the second etalon temperature, detecting that the etalon reaches a temperature range corresponding to an allowable wavelength range corresponding to the second wavelength, and cancelling the suppression of light in response thereto.

Abstract: A method for controlling a wavelength tunable laser is disclosed. The method comprises the steps of: calculating a lasing wavelength from two or more kinds of parameters, the parameters designating the target lasing wavelength; acquiring a driving condition from a memory, the wavelength tunable laser being operable to generate a laser beam of a first wavelength in the driving condition; and calculating another driving condition from the driving condition thus acquired and a wavelength difference between the first wavelength and a second wavelength, the second wavelength corresponding to the lasing wavelength, the wavelength tunable laser being operable to generate a laser beam of the second wavelength in the another driving condition, the wavelength tunable laser being driven in the another driving condition.

Abstract: A method of controlling a wavelength tunable laser to control an oscillation wavelength based on a difference between a detection result of a wavelength by a wavelength detecting unit and a target value, the method includes: acquiring a first drive condition of the wavelength tunable laser to make the wavelength tunable laser oscillate at a first wavelength from a memory; calculating a second drive condition to drive the wavelength tunable laser at a second wavelength by referring to the first drive condition and a wavelength difference between the first wavelength and the second wavelength, the second wavelength differing from the first wavelength; and driving the wavelength tunable laser based on the second drive condition calculated at the calculating of the second drive condition.

Abstract: The method for controlling a wavelength-tunable laser comprises a first step of acquiring a driving condition of the wavelength-tunable laser for laser oscillation at a first wavelength, and a second step of calculating according to the driving condition of the first wavelength and a wavelength difference between the first wavelength and a second wavelength different from the first wavelength a control value or target value of a wavelength characteristic of the second wavelength in the wavelength detection unit, so as to calculate a driving condition for driving the wavelength-tunable laser, the second step including a step of selecting according to the wavelength difference one of etalon slopes having respective gradients identical and opposite to a gradient of an etalon slope used for controlling the first wavelength.

Abstract: A method for controlling wavelength tunable laser comprises the steps of inputting information specifying a first wavelength, determining whether or not the first wavelength is identical to a second wavelength coinciding with any of the fundamental wavelengths stored in the first memory, acquiring a drive condition for the second wavelength from the first memory when it is determined that the first and second wavelengths are identical to each other, calculating a drive condition at the first wavelength, when it is determined that the first and second wavelengths differ from each other, by acquiring the drive condition for the second wavelength from the first memory and using the drive condition according to the difference between the first and second wavelengths, and controlling an lasing wavelength of the wavelength tunable laser according to the drive condition in the acquiring step or calculating step.

Abstract: A method of controlling a wavelength tunable laser to control an oscillation wavelength based on a difference between a detection result of a wavelength by a wavelength detecting unit and a target value, the method includes: acquiring a first drive condition of the wavelength tunable laser to make the wavelength tunable laser oscillate at a first wavelength from a memory; calculating a second drive condition to drive the wavelength tunable laser at a second wavelength by referring to the first drive condition and a wavelength difference between the first wavelength and the second wavelength, the second wavelength differing from the first wavelength; and driving the wavelength tunable laser based on the second drive condition calculated at the calculating of the second drive condition.

Abstract: The method for controlling a wavelength-tunable laser comprises a first step of acquiring a driving condition of the wavelength-tunable laser for laser oscillation at a first wavelength, and a second step of calculating according to the driving condition of the first wavelength and a wavelength difference between the first wavelength and a second wavelength different from the first wavelength a control value or target value of a wavelength characteristic of the second wavelength in the wavelength detection unit, so as to calculate a driving condition for driving the wavelength-tunable laser, the second step including a step of selecting according to the wavelength difference one of etalon slopes having respective gradients identical and opposite to a gradient of an etalon slope used for controlling the first wavelength.

Abstract: A lasing wavelength is controlled so that a wavelength detection result becomes a first target value; selection is made to select either a step of calculating a second target value as a wavelength detection result with a shift of the lasing wavelength, or a step of calculating a third control value of a wavelength characteristic of an etalon for letting a laser lase at a wavelength with a shift of the lasing wavelength; in the former step, the lasing wavelength is controlled so that the wavelength detection result becomes the second target value; in the latter step, the lasing wavelength is controlled so that the wavelength detection result becomes the first target value.

Abstract: The method for controlling a wavelength-tunable laser comprises a first step of acquiring a driving condition of the wavelength-tunable laser for laser oscillation at a first wavelength, and a second step of calculating according to the driving condition of the first wavelength and a wavelength difference between the first wavelength and a second wavelength different from the first wavelength a control value or target value of a wavelength characteristic of the second wavelength in the wavelength detection unit, so as to calculate a driving condition for driving the wavelength-tunable laser, the second step including a step of selecting according to the wavelength difference one of etalon slopes having respective gradients identical and opposite to a gradient of an etalon slope used for controlling the first wavelength.

Abstract: A method for switching a wavelength of a tunable wavelength laser, which is provided with a temperature control device for an etalon and a wavelength detecting section for identifying a wavelength of the laser by a front/back ratio of the etalon, the wavelength of the laser being set in a target wavelength on the basis of a detection result of the wavelength detecting section, and the method comprises: driving the laser at a first wavelength; suppressing output of light of the laser in response to a command indicating an optical output at a second wavelength; starting control of the temperature control device towards a second etalon temperature corresponding to the second wavelength; and before the etalon reaches the second etalon temperature, detecting that the etalon reaches a temperature range corresponding to an allowable wavelength range corresponding to the second wavelength, and cancelling the suppression of light in response thereto.

Abstract: A method for controlling a variable wavelength laser comprises: acquiring information indicating a value of a second wavelength different from a first wavelength, information indicating a wavelength difference with respect to the first wavelength, and a first control value defining wavelength characteristics of an etalon and a first target setting value for the etalon; a second step of selecting the following calculations based on the wavelength difference, the first target setting value and the first control value: calculation of a second target setting value for the etalon; calculation of a second control value defining wavelength characteristics of the etalon; and calculation of the both values; and setting, as the second target setting value, a control target value of a wavelength detection result obtained by a wavelength detecting section, and controlling a wavelength of the variable wavelength laser, if the calculation of the second target setting value is carried out.

Abstract: A method for controlling wavelength tunable laser comprises the steps of inputting information specifying a first wavelength, determining whether or not the first wavelength is identical to a second wavelength coinciding with any of the fundamental wavelengths stored in the first memory, acquiring a drive condition for the second wavelength from the first memory when it is determined that the first and second wavelengths are identical to each other, calculating a drive condition at the first wavelength, when it is determined that the first and second wavelengths differ from each other, by acquiring the drive condition for the second wavelength from the first memory and using the drive condition according to the difference between the first and second wavelengths, and controlling an lasing wavelength of the wavelength tunable laser according to the drive condition in the acquiring step or calculating step.

Abstract: A lasing wavelength is controlled so that a wavelength detection result becomes a first target value; selection is made to select either a step of calculating a second target value as a wavelength detection result with a shift of the lasing wavelength, or a step of calculating a third control value of a wavelength characteristic of an etalon for letting a laser lase at a wavelength with a shift of the lasing wavelength; in the former step, the lasing wavelength is controlled so that the wavelength detection result becomes the second target value; in the latter step, the lasing wavelength is controlled so that the wavelength detection result becomes the first target value.

Abstract: A method for controlling a wavelength tunable laser is disclosed. The method comprises the steps of: calculating a lasing wavelength from two or more kinds of parameters, the parameters designating the target lasing wavelength; acquiring a driving condition from a memory, the wavelength tunable laser being operable to generate a laser beam of a first wavelength in the driving condition; and calculating another driving condition from the driving condition thus acquired and a wavelength difference between the first wavelength and a second wavelength, the second wavelength corresponding to the lasing wavelength, the wavelength tunable laser being operable to generate a laser beam of the second wavelength in the another driving condition, the wavelength tunable laser being driven in the another driving condition.

Abstract: In the method for controlling a tunable wavelength laser, information designating an oscillation wavelength is inputted. A driving condition for causing laser oscillation at a first wavelength is acquired from a memory. A control value of wavelength characteristics of the etalon and a difference between the first wavelength and a second wavelength are referred to, and a control value of wavelength characteristics of the etalon for causing laser oscillation at the second wavelength is calculated. The control value of wavelength characteristics of the etalon are assigned to the tunable wavelength laser, and a wavelength is controlled so that a wavelength sensing result becomes a first target value. Information indicating a wavelength shift amount from the designated oscillation wavelength is inputted. The wavelength sensing result is calculated as a second target value. The wavelength is controlled so that the wavelength sensing result becomes the second target value.

Abstract: A driving condition for causing the tunable wavelength laser to conduct laser oscillation at a first wavelength is acquired. a driving condition for causing the tunable wavelength laser to conduct laser oscillation at the second wavelength is calculated. The tunable wavelength laser is driven based on the driving condition of the second wavelength, feedback control that changes the driving condition of the tunable wavelength laser based on a difference between an output of the wavelength sensing unit and the target value is performed, and the tunable wavelength laser is caused to oscillate at the second wavelength. The driving condition of the tunable wavelength laser obtained by the feedback control when oscillation has occurred at the second wavelength is stored in the memory. Thereafter, the tunable wavelength laser is driven with reference to the stored driving condition of the tunable wavelength laser.