Abstract: A belt and electrocardiographic measurement device, the belt including a belt body windable around an upper arm in a circumferential direction of the upper arm, and an electrode array including a plurality of electrodes fixed to an inner surface of the belt body and arranged side by side in a direction, which is a longitudinal direction of the belt body, the plurality of electrodes being more than N+2 in number, where N is a number of electrodes required for obtaining electrocardiographic information, the electrodes, counted from a first electrode located at a first end in the direction (X) by counting including the first electrode, to the (N+1)th electrode in the direction (X) being arranged at equal intervals that are predetermined intervals, and intervals between each of the (N+1)th and subsequent electrodes being greater than the predetermined interval.

Abstract: A biological information measurement device adapted to be attached on an upper arm of a human body and used thereon includes a belt portion adapted to be wound around the upper arm, electrocardiographic measurement means including a plurality of electrodes for detecting an electrocardiographic signal of the human body, pulse wave measurement means including a pulse wave sensor for detecting a pulse wave of the human body, heartbeat vibration measurement means including a vibration sensor for detecting vibration caused by beating of a heart of the human body, and an analysis processing unit configured to calculate a pre-ejection time and a pulse transit time of the heart based on time series data of the electrocardiographic signal, time series data of the pulse wave, and time series data of the vibration caused by the beating of the heart.

Abstract: A vertical cavity surface emitting laser includes a first distributed Bragg reflector, an active layer, and a second distributed Bragg reflector. The first distributed Bragg reflector, the active layer and the second distributed Bragg reflector are arranged in sequence in the direction of a first axis. The second distributed Bragg reflector includes a semiconductor region and a high resistance region. The high resistance region has an electrical resistance higher than the electrical resistance of the semiconductor region. The first axis passes through the semiconductor region. The high resistance region surrounds the semiconductor region. In a cross section including the first axis, the high resistance region has an inner edge extending in a direction inclined with respect to the first axis such that an inner diameter of the high resistance region increases as a distance from the active layer increases in the direction of the first axis.