Abstract: The present disclosure is to provide a wafer carrier substrate for carrying a wafer on which a plurality of chips is formed, elements to be measured being built in the plurality of chips. The wafer carrier substrate includes: a vacuuming hole for vacuuming of the wafer placed on the wafer carrier substrate; a wafer alignment guide for determining a predetermined position of the wafer placed on the wafer carrier substrate; and a mark for determining a probe contact position. It is possible to recognize a specific shot, without any additional processing of the semiconductor wafer.

Abstract: A structure for blocking light incidence to a peripheral part of an element is applied to a rear surface portion, and when optically coupled to a light receiving element, the light is made incident to a center part of the element without fail. An embodiment relates to a semiconductor light receiving element, including a semiconductor light-absorbing layer on a front surface of a semiconductor substrate, for receiving signal light from a rear surface of the semiconductor substrate, and a transmittance of an inner region of a similar shape having a same center as an operating region defined in the semiconductor light-absorbing layer on the rear surface of the semiconductor substrate is higher than that of an outside of the shape.

Abstract: A swept light source of the present invention keeps a coherence length of an output beam long over an entire sweep wavelength range. A gain of a gain medium is changed with time in response to a wavelength sweep and the coherence length is kept maximum. The gain of the gain medium is kept close to a lasing threshold and an unsaturated gain range of the gain medium is narrowed over the entire sweep wavelength range. An SOA current waveform data acquiring method of driving while keeping the coherence length long, a novel coherence length measuring method, and an optical deflector suitable for the swept light source are also disclosed.

Abstract: This semiconductor wafer has formed therein a plurality of chips, each of which has incorporated therein a semiconductor element to be tested. The semiconductor wafer is characterized by comprising: first pads which are formed on the chips, and to which a plurality of probe needles are connected, the probe needles being connected to the semiconductor elements and used for testing the semiconductor elements; and a second pad that is used for performing a contact check on the probe needles, the second pad having a conductive section greater in length than the distance between the centers of the first pads.

Abstract: A light-receiving device includes a light-receiving element formed on a main surface of a substrate, a light incidence surface formed on a side portion of the substrate at an acute angle or an obtuse angle with respect to the plane of the substrate and having an inclined surface forming one plane, and a lens for focusing light incident on the light-receiving element. The lens is disposed at a position where the light incident from the light incidence surface is reflected on a side of a back surface of the substrate.

Abstract: A light receiving element enables light incidence from the upper surface of a light receiving element while realizing a structure in which the optical path length is extended, and as a result, facilitates optical mounting. A light receiving element in which a first semiconductor layer, a light absorbing layer composed of a semiconductor, a second semiconductor layer, a first electrode formed in contact with the first semiconductor layer, and a second electrode formed in contact with the second semiconductor layer and including a first reflective layer composed of a metal are formed on an upper surface of a substrate, wherein incident light is incident from the upper surface of the substrate, reflected by the bottom surface of the substrate, and then incident on the light absorbing layer obliquely to the vertical direction.

Abstract: There is provided an element structure of an avalanche photodiode that can operate in a high gain state while having high reliability and low noise property. There is produced an avalanche photodiode including at least a multiplication layer and a light absorbing layer between first and second semiconductor contact layers, in which an area of the first semiconductor contact layer is at least smaller than an area of the multiplication layer, the avalanche photodiode having an electric field relaxation layer configured to be depleted at an operating voltage between the first semiconductor contact layer and the multiplication layer.

Abstract: A swept light source of the present invention keeps a coherence length of an output beam long over an entire sweep wavelength range. A gain of a gain medium is changed with time in response to a wavelength sweep and the coherence length is kept maximum. The gain of the gain medium is kept close to a lasing threshold and an unsaturated gain range of the gain medium is narrowed over the entire sweep wavelength range. An SOA current waveform data acquiring method of driving while keeping the coherence length long, a novel coherence length measuring method, and an optical deflector suitable for the swept light source are also disclosed.

Abstract: A swept light source of the present invention keeps a coherence length of an output beam long over an entire sweep wavelength range. A gain of a gain medium is changed with time in response to a wavelength sweep and the coherence length is kept maximum. The gain of the gain medium is kept close to a lasing threshold and an unsaturated gain range of the gain medium is narrowed over the entire sweep wavelength range. An SOA current waveform data acquiring method of driving while keeping the coherence length long, a novel coherence length measuring method, and an optical deflector suitable for the swept light source are also disclosed.

Abstract: A swept light source of the present invention keeps a coherence length of an output beam long over an entire sweep wavelength range. A gain of a gain medium is changed with time in response to a wavelength sweep and the coherence length is kept maximum. The gain of the gain medium is kept close to a lasing threshold and an unsaturated gain range of the gain medium is narrowed over the entire sweep wavelength range. An SOA current waveform data acquiring method of driving while keeping the coherence length long, a novel coherence length measuring method, and an optical deflector suitable for the swept light source are also disclosed.