A smoke detector includes a laser light source to provide incident light. The smoke detector also includes a Fabry-Perot etalon to transmit some incoming light, which is produced from the incident light, as transmitted light. Smoke particles in a cavity of the Fabry-Perot etalon affect an intensity of one or more wavelengths of the transmitted light.

An elderly care and security system comprises one or more networked lighting luminaire installed in a room, the luminaire comprising: one or more sensors configured to: detect a fall; detect smoke; detect glass break; detect presence of another person in the room while the elderly person is lying in bed; and detect presence of a person while an alarm system is active and detect no presence for a period longer than a predetermined time interval; a lighting unit controlled to adaptively illuminate the room; a wireless bi-directional transceiver, loudspeaker and microphone, configured to be activated automatically for communication with the elderly person, a caregiver or relative; a door locking/unlocking unit with connectivity to an electrical door lock, configured to automatically lock/unlock a door of a safe room for the elderly person; and an alarm activating unit, configured to automatically activate/deactivate an alarm.

An elderly care and security system comprises one or more networked lighting luminaire installed in a room, the luminaire comprising: one or more sensors configured to: detect a fall; detect smoke; detect glass break; detect presence of another person in the room while the elderly person is lying in bed; and detect presence of a person while an alarm system is active and detect no presence for a period longer than a predetermined time interval; a lighting unit controlled to adaptively illuminate the room; a wireless bi-directional transceiver, loudspeaker and microphone, configured to be activated automatically for communication with the elderly person, a caregiver or relative; a door locking/unlocking unit with connectivity to an electrical door lock, configured to automatically lock/unlock a door of a safe room for the elderly person; and an alarm activating unit, configured to automatically activate/deactivate an alarm.

An emergency lighting system including a light source, a variable constant current drive, an emergency alarm, and a controller. The light source includes a first light channel that produces light at a first correlated color temperature and a second light channel that produces light at a second correlated color temperature that is less than the first correlated color temperature. The variable constant current drive is configured to supply DC current to the first light channel and the second light channel. The emergency alarm is configured to be triggered upon detecting the presence of an emergency condition. The controller is configured to determine whether the emergency alarm is triggered, increase the DC current supplied to the first light channel when the emergency alarm is not triggered, and decrease the DC current supplied to the first light channel when the emergency alarm is triggered.

An emergency lighting system including a light source, a variable constant current drive, an emergency alarm, and a controller. The light source includes a first light channel that produces light at a first correlated color temperature and a second light channel that produces light at a second correlated color temperature that is less than the first correlated color temperature. The variable constant current drive is configured to supply DC current to the first light channel and the second light channel. The emergency alarm is configured to be triggered upon detecting the presence of an emergency condition. The controller is configured to determine whether the emergency alarm is triggered, increase the DC current supplied to the first light channel when the emergency alarm is not triggered, and decrease the DC current supplied to the first light channel when the emergency alarm is triggered.

A receiver comprises: optical signal distributing means for distributing an optical signal transmitted to detect a detection target on a traveling path to two or more paths; a detection unit configured to detect a received light intensity of the optical signal at a first position where the received light intensity increases when the optical axis is shifted and at a second position where the received light intensity decreases; an intensity ratio calculation unit configured to calculate a ratio between the received light intensity at the first position and the second position based on the output of the detection unit; and a determination unit configured to determine whether or not there is an optical axis shift based on a change in the ratio of the received light intensity calculated by the intensity ratio calculation unit.

A receiver (10) according to the present disclosure includes: a detection unit (11) including a sensor configured to receive a first optical signal of a wavelength included in an absorption band of water molecules and a second optical signal of a wavelength included in an absorption band of carbon dioxide molecules, a signal processing unit (12) configured to calculate a water vapor concentration and a carbon dioxide concentration from changes of intensities of the first and second optical signals, and a determination unit (13) configured to determine whether or not there is a fire that is caused by alcohol combustion based on the water vapor concentration and the carbon dioxide concentration.

A receiver (10) according to the present disclosure includes: a detection unit (11) including a sensor configured to receive a first optical signal of a wavelength included in an absorption band of water molecules and a second optical signal of a wavelength included in an absorption band of carbon dioxide molecules, a signal processing unit (12) configured to calculate a water vapor concentration and a carbon dioxide concentration from changes of intensities of the first and second optical signals, and a determination unit (13) configured to determine whether or not there is a fire that is caused by alcohol combustion based on the water vapor concentration and the carbon dioxide concentration.

The present invention relates to a gas measuring system for measuring the presence of a predetermined gas including a light source and a light receiver separated by a gas volume, the light source emitting light within a chosen range of wavelengths including characteristic absorption wavelengths of the gas to be measured and the light receiver being capable of detecting light in said wavelength range and the system including a spectrum analyzer and a storage means for storing the specific absorption wavelengths of the gas thus to recognize a gas absorbing at said specific wavelengths. The storage means also includes specific absorption wavelengths characterizing at least one other material having absorption wavelengths partially overlapping the absorption wavelengths of said gas, and thus detect the material in the volume. The system includes an analyzer unit being adapted to detect said other material from the gas measurements so as to distinguish between said material and gas in the volume, and to provide a measure of said gas.

The present disclosure discloses an infrared sensor, an infrared gas detector and an air quality detection device. The infrared sensor includes electrodes, a substrate, an isolation layer and a graphene film. The graphene film has a periodical nanostructure. The infrared sensor enhances the absorption of infrared light, and is capable of only absorbing specific infrared wavelengths, thus improving the selective performance of the infrared gas detector.