Source follower circuit, laser driving apparatus, semiconductor laser apparatus, current-voltage convertion circuit, and light receiving circuit

A source follower circuit comprising:

• a source follower stage comprising first, second, and third III-V compound semiconductor transistors connected in series between a first power line and a second power line, each of said first, second, and third III-V compound semiconductor transistors having a source, a drain, and a gate thereof;
• and
• a bias stage having a first node for providing a first bias voltage, a second node for providing a second bias voltage, and a first circuit portion provided to generate said second bias voltage smaller than said first bias voltage,
• wherein said gate of said first III-V compound semiconductor transistor is coupled to an input of the source follower circuit,
• wherein said source of said first III-V compound semiconductor transistor is coupled to an output of the source follower circuit,
• wherein said gate of said second III-V compound semiconductor transistor is electrically connected to said second node,
• wherein said gate of said third III-V compound semiconductor transistor is electrically connected to said first node,
• wherein said third III-V compound semiconductor transistor is electrically connected between said source of said first III-V compound semiconductor transistor and said drain of said second III-V compound semiconductor transistor.