Devices, systems and methods for detecting particles

A particle detector, comprising:

• a housing comprising a sample inlet and a sample outlet, and enclosing a detection cavity having a cavity length along a longitudinal axis, wherein the housing defines a flow path for a sample fluid from the sample inlet, through the detection cavity, and to the sample outlet, wherein the detection cavity comprises a first detection zone and a second detection zone downstream from the first detection zone;
• a first light source configured for directing a first irradiating light to particles of the sample fluid flowing in the first detection zone;
• a second light source configured for directing a second irradiating light to particles of the sample fluid flowing in the second detection zone;
• and
• a photo-responsive material facing the detection cavity and positioned along at least a portion of the cavity length at a radial distance from the longitudinal axis, wherein the photo-responsive material is configured for receiving measurement light propagating from the particles in a plurality of measurement light paths angled relative to the longitudinal axis.

A particle detector, comprising:

• a housing comprising a sample inlet and a sample outlet, and enclosing a detection cavity having a cavity length elongated along a longitudinal axis, wherein:
• the housing defines a flow path for a sample fluid from the sample inlet, through the detection cavity, and to the sample outlet along the longitudinal axis;
• the sample inlet comprises an axial inlet section on the longitudinal axis;
• the sample outlet comprises an axial outlet section on the longitudinal axis;
• the sample outlet comprises an axial outlet section on the longitudinal axis;
• the axial inlet section and the axial outlet section having respective maximum radial dimensions along a radial direction orthogonal to the longitudinal axis;
• and
• the detection cavity has a characteristic dimension in a range from 0.1% to 200% greater than the characteristic dimension of the axial inlet section and the axial outlet section;
• a light source configured for directing irradiating light through the detection cavity along the longitudinal axis to particles of the sample fluid flowing in the detection cavity;
• and
• a photo-responsive material facing the detection cavity and positioned along at least a portion of the cavity length at a radial distance from the longitudinal axis, wherein the photo-responsive material is configured for receiving measurement light propagating from the particles in a plurality of measurement light paths angled relative to the longitudinal axis.

A particle detector, comprising:

• a housing comprising a sample inlet and a sample outlet, and enclosing a detection cavity having a cavity length elongated along a longitudinal axis, wherein the housing defines a flow path for a sample fluid from the sample inlet, through the detection cavity, and to the sample outlet along the longitudinal axis;
• a light source configured for directing irradiating light through the detection cavity along the longitudinal axis to particles of the sample fluid flowing in the detection cavity;
• a plurality of mirrors in the detection cavity, wherein:
• the detection cavity has a dimension along a transverse axis orthogonal to the longitudinal axis;
• and
• the mirrors are configured for reflecting the irradiating light one or more times such that the irradiating light traverses the detection cavity two or more times along directions having a component along the transverse axis;
• and
• a photo-responsive material facing the detection cavity and positioned along at least a portion of the cavity length at a radial distance from the longitudinal axis, wherein the photo-responsive material is configured for receiving measurement light propagating from the particles in a plurality of measurement light paths angled relative to the longitudinal axis.

A particle detector, comprising:

• a housing comprising a sample inlet and a sample outlet, and enclosing a detection cavity having a cavity length along a longitudinal axis, wherein the housing defines a flow path for a sample fluid from the sample inlet, through the detection cavity, and to the sample outlet;
• a light source configured for directing irradiating light along the longitudinal axis to particles of the sample fluid flowing in the detection cavity;
• a beam chopper configured for chopping the irradiating light;
• and
• a photo-responsive material facing the detection cavity and positioned along at least a portion of the cavity length at a radial distance from the longitudinal axis, wherein the photo-responsive material is configured for receiving measurement light propagating from the particles in a plurality of measurement light paths angled relative to the longitudinal axis.