Fiber assembly for respiratory gas detection

A respiratory gas detection device, comprising:

• a fiber assembly including
• a housing including a respiratory gas detection chamber,
• a collimator rigidly disposed within or detachably attached to the housing,
• a retroreflector rigidly disposed within or detachably attached to the housing and optically aligned within the housing across the respiratory gas detection chamber with the collimator, and
• a single mode optical fiber optically aligned with the collimator within or external to the housing to emit a gas sensing light beam through the collimator across the respiratory gas detection chamber to the retroreflector and to receive a gas detection light beam reflected from the retroreflector across the respiratory gas detection chamber through the collimator to the single mode optical fiber,
• wherein the gas detection light beam is indicative of the degree of carbon dioxide or oxygen within any gas flowing through the respiratory gas detection chamber;
• and
• an optical control assembly optically coupled to the single mode optical fiber, the optical control assembly including
• a laser for generating the gas sensing light beam,
• a light detector for detecting the gas detection light beam, and
• an optical fiber circulator or optical fiber coupler structurally configured to direct the gas sensing light beam from the laser to the single mode optical fiber and to direct the gas detection light beam from the single mode optical fiber to the light detector.